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  1. #1
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    Wren 150mm Tuning/Setup Guide

    My Wren is supposed to arrive soon, and I have seen lots of minor notes on other threads both in Fat Bikes and Foes about the fork. I wanted to make this single thread so riders could post what their setup is in terms if pressure, dampening, etc.

  2. #2
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    I have been riding a Wren 150mm for a month. In Cold weather and in milder Winter weather with rain. The pressure is changing significant when the temperature is changing a lot. Checked the sag latest today, and I was getting 25% sag when running 55psi on top and bottom. The bottom air Chamber can be runned a bit lower to get more small bump plushness and opposite to get more feedback from the ground. Still doing test rides at different air pressure. The confusing part is that when increasing either Chamber the other will shrink and the pressure will increase. So I think the way to og is to just fill it up so the pressure is in Balance (top/bottom) and then ad pressure. The Reading you will find different, but you need just to note the change in pressure.

  3. #3
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    Large Foes Mutz, 26 x 4" On One Floaters
    CC Inline 5.5", 130-140psi, near factory setting, a little more active LSR
    Wren 150mm, 60 psi/60psi, full open dampener control.
    Me: 195# nakid.

    First ride, ten miles on dirt single track, some out of the seat climbing, some low angle jumps, nothing significant.

    Out of the box I noticed stanchion stikiness not unlike the Bluto. The stikiness improved somewhat with riding, but could probably benefit from some more to break in. I wonder whether this stikiness could be due to having an overly slack HTA (65deg) or there's some flex related "binding" at the seals.

    The initial dampening was excessive, so much so that it noticeably slowed the leg return.

    Anyone brave enough to try and change oil in the dampener unit? Would this void the warranty?

  4. #4
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    I felt also the stickiness when it was new, but it will got away after a while. It is smooth as butter now, and had the same feeling if the head angle was the problem. I have actually dismantled the air side, and it is no signs of wear on the keys yet. The grease had changed a little bit of color some places, from white to grey, but that I think is pretty normal. They use a lot of grease in there btw. The oil is 2.5 grade, so should be thin enough- so is it necessary to get a thinner grade? How is the rebound working on your fork Nurse Ben? Mine is actually doing it going in slow motion when used at max setting. If I did not misunderstand, the damping is only interfering with the high speed compression (like the small knob on the RCT damping unit on the Bluto), not the low speed, until you go full turn, then you have a locked. That is why you do not get very little change, but it works fine for me at high speed damping.

  5. #5
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    Quote Originally Posted by Rumblefish2010 View Post
    I felt also the stickiness when it was new, but it will got away after a while. It is smooth as butter now, and had the same feeling if the head angle was the problem. I have actually dismantled the air side, and it is no signs of wear on the keys yet. The grease had changed a little bit of color some places, from white to grey, but that I think is pretty normal. They use a lot of grease in there btw. The oil is 2.5 grade, so should be thin enough- so is it necessary to get a thinner grade? How is the rebound working on your fork Nurse Ben? Mine is actually doing it going in slow motion when used at max setting. If I did not misunderstand, the damping is only interfering with the high speed compression (like the small knob on the RCT damping unit on the Bluto), not the low speed, until you go full turn, then you have a locked. That is why you do not get very little change, but it works fine for me at high speed damping.
    I do need more ride time, but it'll have to be next weekend as the local snow is shite and I don't feel like riding gravel.

    I'll keep thrashing on it, but it has a very slow return, so that needs to change.

    Only 2.5 wt oil??

    As to the lock out, wow!, that's the first lockout I have used that actually locks the fork. I forgot to mention that in my review, but it's worthy for sure.

    I didn't seem to notice any progression in the rebound, only locked and unlocked.

  6. #6
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    I think you need to run the fork for a few weeks until it should work properly. Until it is proper broken in, you will find things it a bit strange. What do you mean with “only 2,5w”, is that oil to thick? The rebound adjustment will also change dramatic after time of use. Try to use the compression adjustment like a high speed adjustment.

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    Subcribe.

  8. #8
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    you'd definitely benefit from lighter fork oil, that should speed up rebound damping, especially in the cold. You should talk to Wren first, but someone like Max at Traxxion Dynamics ( Bicycle Suspension Services ) could improve the valving in the compression and rebound circuits. It would be custom work, but if anyone has the capability, it would be them, as they've been manufacturing cartridges for motorcycle forks for years.

  9. #9
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    Quote Originally Posted by Rumblefish2010 View Post
    I think you need to run the fork for a few weeks until it should work properly. Until it is proper broken in, you will find things it a bit strange. What do you mean with “only 2,5w”, is that oil to thick? The rebound adjustment will also change dramatic after time of use. Try to use the compression adjustment like a high speed adjustment.
    I've had a few forks over the years, so the idea of break in is not new to me. The Wren takes break-in to another level, which suggests that break-in alone is not going to be enough, but time will tell. If I had a machine that could cycle the fork a few thousand times, that would be an interesting before and after test.

    5-10wt oil is typical, so 2.5wt is pretty light, which is why I was wondering if that is accurate. If it is only 2.5wt, that makes going to a lighter weight oil kinda tough.

    The Damper is a closed unit, so I'm not sure what can be done to improve it other than a redesign. I can't imagine that Wren wants to send their forks to a custom shop for revalving, though one user has already done that.

    I'm not prepared to send my brand new fork to a custom shop, that seems like a strange proposition ... shouldn't the fork work as designed?

    The Compression damper didn't work except as a lockout, so I just left it open. Same with the dampener adjuster, it didn't really work, so I left it open.

    I'd like to hear more from the Foes guys who tested the fork initially...did they start with a broken in fork or did they do an install straight from the box? Was it a production Wren? Did they make any changes? Did they notice any break in issues?

    If I had tried this fork new on a floor model bike, I would have passed. If break in proves you right, then we'll see that in time. I already paid the piper, so I'll ride it until I don't.

  10. #10
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    I have one of the 150mm forks. It was more or less DOA out of the box. Problems with the air spring, problems with the damper, problems with the seals and seal heads.

    To their credit, Wren have been great to talk to and are having me send the fork to Jerry @ Hippie Tech (on their dime -- parts, labor, and shipping both ways) to diagnose and fix.

    I'll be out of the shop starting Monday, and for the next few weeks, so it'll be early Feb before I can get the fork back and ridden. Will check back in here then.

  11. #11
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    I just spoke to Russ at Wren central, I told him about my damper issues, he's going to check with the factory. Since my damper adjuster only turns ~3.5 rotations and my lock out is functional, he does not believe the fork was assembled incorrectly. He may send me a replacement damper cartridge.

    Russ said that future forks will be shipped with a travel adjustment clip "pack" consisting of a 10mm and 20mm clip, this will allow reducing travel to 140mm, 130mm, or 120
    Last edited by Nurse Ben; 01-15-2016 at 11:03 AM.

  12. #12
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    The Clip that followed the fork is only limitating the travel, it is not lowering the fork.

  13. #13
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    Quote Originally Posted by Rumblefish2010 View Post
    The Clip that followed the fork is only limitating the travel, it is not lowering the fork.
    THE CLIPS DO CHANGE FORK LENGTH.

    Clarification from WREN:

    "Hi Ben!
    Yes the clips reduce travel and length. You can stop down to 140, 130 or 120. Use 1-10mm to go to 140, use 1 - 20mm to go to 130 and use both to go to 120. When using the 20mm it always goes on first and right up against the top of the air spring. The 20mm has one more open side, that side goes on top (faces up). If you use both, the 10mm goes under the 20.

    Regards,

    Russ Johnson
    Wren Sports, LLC"

  14. #14
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    Okay, that was good to clarify then. I was certain the Clip will only be a bump stop, limitating the travel- I must have misunderstood what has been said and how it Works. Sorry for that! It says "stop Down" but I assume it should be step Down??

  15. #15
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    No worries, I think this design is a big positive to the Wren, changing travel on a Bluto is time consuming and not free. With thd Wren you could easilly use this fork across multiple platforms or use the ease of travel adjustment to play with "trim".

  16. #16
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    Think I have found out a way to fill air in the fork now. Fill the air Chambers With similar air pressure in both Chambers. Start then to increase or decrease the air pressure in the bottom air Chamber. Think about the bottom air Chamber as you will add or remove tokens to an ordinary fork. This means you will be able to find the accurate bottom out resistance, since you can just dial in by a small amount of change of pressure with the pump. The compression knob works on my fork, but it is not working really progressive. You can feel small clicks on the knob, but it actually is 100% locking in the two last clicks. I wished it was more progressiv before it was locked in the last click. You can feel a small bit of change in compression. It is added a small portion of compression only, when you start from zero and go click by click. The rebound is working too good, going into a to small movement after 2 turns. I Wonder if it Could be too little or too much oil in the fork, causing these problems???
    Last edited by Rumblefish2010; 01-17-2016 at 03:10 AM.

  17. #17
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    Sorry for knagging about these, but I cannot se how these travel Clips, could reduse length of the fork, when you look at the drawing. If I am correct, the Clip will sit on top to the left, that is not at the part that is not moving. I cannot see how to With a Clip to change the length??Wren 150mm Tuning/Setup Guide-wren-fork.jpg

  18. #18
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    Quote Originally Posted by Rumblefish2010 View Post
    Sorry for knagging about these, but I cannot se how these travel Clips, could reduse length of the fork, when you look at the drawing. If I am correct, the Clip will sit on top to the left, that is not at the part that is not moving. I cannot see how to With a Clip to change the length??Click image for larger version. 

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    Nor can I, but the clips are on the way, I'm going to reduce travel to 140mm, so I'll let you know how it works.

    No rides this past week, doing a big two bathroom remodel, weather has been spotty, I'm heading to Spokane this Wednesday for a vet visit, dropping the dog off for the day, so I'll scout some trails and give the Wren a good workout.

    Even though there are some quirks with the Wren, I still like it much better than the Bluto.

  19. #19
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    Quote Originally Posted by Nurse Ben View Post
    Nor can I, but the clips are on the way, I'm going to reduce travel to 140mm, so I'll let you know how it works.

    No rides this past week, doing a big two bathroom remodel, weather has been spotty, I'm heading to Spokane this Wednesday for a vet visit, dropping the dog off for the day, so I'll scout some trails and give the Wren a good workout.

    Even though there are some quirks with the Wren, I still like it much better than the Bluto.
    I have been riding Wren Down to 0 fahrenheit now, and it is still no issues. The Bluto did all kind of strange Things....I do not even compare it With the Bluto.....

  20. #20
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    I had a nice mixed ride today, corny snow, dirt, rock, pine duff, nothing too serious but it gave me more time to play with the air pressures and increase break in.

    I tried running higher pressure in the lower (75psi) and lower pressure in the upper (50 psi ) and the end result was a very supple fork with 25-30% sag, no issues with bottoming out.

    I know it's not supposed to work that way, but it seemed to make the fork function as deigned. The only way I could get the same level of "suppleness" was using lower pressures on top and bottom, which slowed rebound.

    I also tried 50psi on top and zero psi on the bottom, what was strange is that it didn't feel that much different from 50psi/50psi.

    So, in summary, I do like the fork, it is stiff and burly, the dampening seems to be improving (break in?), and I have been able to dial in a decent level of function. A real test will be an all day ride at Tiger, but the weather ain't gonna be warm and dry for a while.

    St. George in March!

    and yes Dorothy, the Wren is oodles better than the Bluto. In fact, it's so good that I'd buy one

  21. #21
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    Quote Originally Posted by Nurse Ben View Post
    and yes Dorothy, the Wren is oodles better than the Bluto. In fact, it's so good that I'd buy one

    Quote Originally Posted by Nurse Ben View Post
    If I had tried this fork new on a floor model bike, I would have passed. If break in proves you right, then we'll see that in time. I already paid the piper, so I'll ride it until I don't.
    Im glad to see your opinion changed in one week.

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    As I read all these observations, adjustments, and what not, I couldn't help but think... "Why can't they just make a plug and play fork that would serve its purpose and my objectives in the first mile and the thousandt mile without me having to take a degree in engineering?"

    I guess I will pass on this one and stick with the steel ICT fork.

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    Don't shoot, but I think those that are the pickiest about fork performance are those that tend to have the skill set to make modifications.

    For those of us laymen that aren't as comfortable tearing a fork apart, I suspect we notice less and aren't as sensitive to the forks function.

    But that's just my guess.

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    We the people ...

    Has it been a week already?

    Nope, two weeks, but who's counting

    I still think the rebound is slow, but I have seen some improvement and varying the pressure in a "weird way" has been an interesting experiment.

    The Bluto is just so bad, I mean who in their right mind would put a Reba level fork on a big hit bike? Anyway, the point is that the Bluto was such a poor choice for this aplicatiopn that it would n't take much to improve the situation.

    The Wren checks off most of the boxes:

    Stiff/Robust
    Not too heavy
    Long travel
    Not too expensive
    150mm TA
    Responsive mfg
    No stiction

    The only question remaining is the slow rebound and quirky damper. I think the rebound is improving with use, I think playing with pressures has made a difference, and I'm confident that Wren will make this fork happen.

    Buying a fork like the Wren is still a crap shoot no matter how you cut it. Wren is a small company and this is their only fork; they are not a suspension mfg. per se.

    More to come as I get ride time on non snowy surface

    Quote Originally Posted by kntr View Post
    Im glad to see your opinion changed in one week.

  25. #25
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    Quote Originally Posted by Shinkers View Post
    Don't shoot, but I think those that are the pickiest about fork performance are those that tend to have the skill set to make modifications.

    For those of us laymen that aren't as comfortable tearing a fork apart, I suspect we notice less and aren't as sensitive to the forks function.

    But that's just my guess.
    Nah, I suck

    I'd call myself an "every person" rider, I'm not great, I ride hard, I've been riding wheel contraption for a long time, I work on my own stuff, and I know a few things about how things work.

    I don't want anyone making a choice because I misled them, so I tell what I think, sometimes I change my mind, but for the most part I say what I believe is true.

    It would be wonderful if we had a "ready to go burly fork", but this is just a fringe area of biking that hasn't seen a lot of play, so we just gotta go with it.

    It could be worse, we could be talking about telemark bindings...

    Nah, don't go there

  26. #26
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    For me the Wren fork is the only option, since I am riding fat bike all year round With wide tires (4.8" is too wide for boost forks), there is no other. The Bluto was just making me angry

    I think Wren have the ambitions to make these fork work regarding rebound and compression.

    I mean it is a positive thing that it is exactly a small manufacturer behind these fork, it would have been a totally different story With one of the big manufacturers. They would give a damn about feedback from the customers.....

  27. #27
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    I have just got the user manual for the fork, and there is ONLY travel adjustment limiting options, not a travel length adjustment. The Clip is pushing the bumper that stops the travel lower, to limit the travel. That confirms what I meant before from the drawing of the fork and where the Clips sits. Here is from the user manual:

    "Before your first ride you should check if you have enough tire to crown clearance. This
    fork comes standard with either 110 mm or 150 mm of travel from the factory. If you are
    using narrow rims and big tires, you must check if you have enough clearance between
    your crown and tire before you ride with this fork. If you do not have enough clearance,
    the air spring needs to be modified with a stopper(s) that will give you the proper
    clearance. Stoppers are sold separately and can modify the travel in 10 mm increments.
    !
    150 mm of travel - pre-set at factory
    For 140 mm of travel - remove the pre-installed 10 mm clip and insert 1 - 20 mm clip.
    For 130 mm of travel - leave the 20 mm clip in place and add the 10 mm UNDERNEATH. The
    20 mm must be on top."

  28. #28
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    Yes, it doesn't make sense, I read the same info in an email I got from Wren.

    I'll ask my buddy what he thinks; he's an ex Manitou fork team engineer.

    How does the Dorado adjust by using air pressure? Could that be part of the equation?
    Quote Originally Posted by Rumblefish2010 View Post
    I have just got the user manual for the fork, and there is ONLY travel adjustment limiting options, not a travel length adjustment. The Clip is pushing the bumper that stops the travel lower, to limit the travel. That confirms what I meant before from the drawing of the fork and where the Clips sits. Here is from the user manual:

    "Before your first ride you should check if you have enough tire to crown clearance. This
    fork comes standard with either 110 mm or 150 mm of travel from the factory. If you are
    using narrow rims and big tires, you must check if you have enough clearance between
    your crown and tire before you ride with this fork. If you do not have enough clearance,
    the air spring needs to be modified with a stopper(s) that will give you the proper
    clearance. Stoppers are sold separately and can modify the travel in 10 mm increments.
    !
    150 mm of travel - pre-set at factory
    For 140 mm of travel - remove the pre-installed 10 mm clip and insert 1 - 20 mm clip.
    For 130 mm of travel - leave the 20 mm clip in place and add the 10 mm UNDERNEATH. The
    20 mm must be on top."

  29. #29
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    I'm very interested in whether a travel adjustment alters the a-c height. 570mm is a non starter for me, it's just too much of a jump from the relatively low a-c of the bluto

    Sent from my SAMSUNG-SM-N910A using Tapatalk
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  30. #30
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    I sent an email to Russ, he's been pretty responsive, I'll let you know...

    Quote Originally Posted by rollertoaster View Post
    I'm very interested in whether a travel adjustment alters the a-c height. 570mm is a non starter for me, it's just too much of a jump from the relatively low a-c of the bluto

    Sent from my SAMSUNG-SM-N910A using Tapatalk

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    How did you guys mount the carbon leg guards? I was thinking a small piece of tube and two zip ties per leg.... but any suggestions would be great. Thanks.

  32. #32
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    Double sided tape and zip ties.

    Quote Originally Posted by JCHKeys View Post
    How did you guys mount the carbon leg guards? I was thinking a small piece of tube and two zip ties per leg.... but any suggestions would be great. Thanks.

  33. #33
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    And just to make sure, it only fits on the bottom 1/2 inch of the actual stantion, and not the base fitting where the axle mounts....

  34. #34
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    Quote Originally Posted by JCHKeys View Post
    And just to make sure, it only fits on the bottom 1/2 inch of the actual stantion, and not the base fitting where the axle mounts....
    Yes. On the Stanchion, I measured the travel and it stops with enough stanchion remaining to mount the guards.

  35. #35
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    Quote Originally Posted by Nurse Ben View Post
    I sent an email to Russ, he's been pretty responsive, I'll let you know...
    Russ wrote back, he said he was mistaken, travel changes but length does not change fork length:

    "Hi Ben!

    Sorry it took so long to get back to you I’ve been traveling today. First, I must apologize that I gave you bad info last time. Out travel clips limit travel only, do not affect AC. Our clips clip onto the air spring rod outside of the air chamber. Not sure what I was thinking at the time. We offer the Wren fork in 505, 530 and 570 AC lengths to work with most frame geometries. Hope this helps. Sorry for the brain fade earlier!"

    I wrote Russ back and asked him if there would be air shafts available for changing fork length, no response yet.

  36. #36
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    So I mounted up my Wren and did the first test right last night. There is definitely a loose feel, but side by side with my other fat bike with a Bluto, doing the simple test of holding the front wheel with my knees and turning the handlebars, there was a difference. The wren had a very loose feeling for about 3/4 inch turn of the handlebars, but then became solid and wouldn't move any more. The bluto felt like a wet noodle where I could put more force and keep twisting the handlebars.

    So are the Wren doesn't have as much breaking twist as the Bluto, but this has only been street riding as my trails still have a foot of snow on them.

    Has anyone gotten their fork back from any servicing by Wren or Hippie Tech? Were they able to fix this looseness?

    Oh and when I dumped out the Wren box, two awesome clamps for the carbon guards dropped out, so much nicer than my hokie zip ties.

  37. #37
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    Quote Originally Posted by Nurse Ben View Post
    Russ wrote back, he said he was mistaken, travel changes but length does not change fork length:

    "Hi Ben!

    Sorry it took so long to get back to you I’ve been traveling today. First, I must apologize that I gave you bad info last time. Out travel clips limit travel only, do not affect AC. Our clips clip onto the air spring rod outside of the air chamber. Not sure what I was thinking at the time. We offer the Wren fork in 505, 530 and 570 AC lengths to work with most frame geometries. Hope this helps. Sorry for the brain fade earlier!"

    I wrote Russ back and asked him if there would be air shafts available for changing fork length, no response yet.
    This is a major bummer for me. I was hoping to run a 150mm @ 130mm with an a-c of 550 (+19mm from my 120mm bluto). I can only wait and hope they make a shorter air shaft to allow a more reasonable a-c height.

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  38. #38
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    Yes, you can have your cake and eat it too!

    Russell got back to me "again" and he said that there is a way to change A-C when travel is reduced. He had re-writen the manual to include text that describes the process. I'll post the revised manual when I get to work on Tuesday, in the meantime I will post yhe added text:

    Air Spring Travel and AC Length Modification and Assembly:
    You can reduce travel and the AC Length of the fork by placing the travel clips INSIDE the air spring.
    1. Follow steps 1 through 4 above to remove the stanchion with the air spring from the fork. Be sure ALL air is
    released from the air spring.
    2. Looking at the top of the air spring, you will see a silver cap with 2 holes. This is the stanchion assembly cap.
    Using a pair of bent nose pliers in the holes, unscrew the cap completely.
    3. Grip the top of the air spring firmly and pull it out of the stanchion. This may take some effort.
    4. Locate the Small Steel Spring at the bottom of the air spring. The clips will be installed on TOP of that spring
    and below the white plastic bumper above that spring. The clips snap onto the rod same as above.
    5. If only one clip is used, it must be the 20 mm clip because it is designed to rest on the spring. Remember that
    the wide-mouth side of the 20 mm clip must face up. The 10 mm clip should only be used with the 20 mm clip
    and must be installed on TOP of the 20 mm clip.
    6. Be sure the Large Steel Spring is well greased. All coils should be “filled” with grease. If riding in cold
    weather, be sure to use a grease specified for use in the temperature you will be riding in.
    7. Lightly grease the air piston seals and insert the air spring back into the stanchion. CAREFULLY thread the
    stanchion assembly cap back into the stanchion making sure not to cross thread the cap. Tighten securely
    with the bent nose pliers.
    8. Now reverse steps 1 to 4 from the travel modification section and install the stanchion into the fork. Be sure to
    check your air pressure.


    Quote Originally Posted by rollertoaster View Post
    This is a major bummer for me. I was hoping to run a 150mm @ 130mm with an a-c of 550 (+19mm from my 120mm bluto). I can only wait and hope they make a shorter air shaft to allow a more reasonable a-c height.

    Sent from my SAMSUNG-SM-N910A using Tapatalk

  39. #39
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    Here's the revised Wren manual, sorry for the low quality and lack of formatting

    Page 1
    Wren
    Inverted
    Suspension
    Fork
    with Keyed Stanchions

    and TwinAir System
    Owners Manual
    ________________________________________
    Page 2
    Congratulations!
    You have just purchased a Wren Inverted Suspension Fork. The culmination of years of design, testing and riding.
    Please read this entire owner’s manual carefully before riding to learn about all the possibilities this fork
    offers to you. Please make sure that you follow the safety and maintenance instructions strictly.
    Quick explanation of the fork
    Modular Fork:
    This fork is assembled and designed from a modular point of view. This means all parts can be exchanged for
    new parts when needed. These parts can be ordered from your local dealer or service center. However, we prefer
    that the exchange of parts and any service to internal parts be done by one of the certified service centers that we
    have appointed. If your country has no service center available, the fork may be returned to our factory for
    service. If a fork is serviced by anyone other than a certified service center, the consumer warranty will void.
    Please refer to page 5 for complete fork description.
    Fork Features
    Hydraulic Damping with Adjustable Compression and Rebound (right leg):
    The hydraulic oil damper is a sealed unit and designed to be replaced by a certified service center. You can
    modify the fork’s ride feel by changing the presets as described later in this manual.
    Air Spring (left leg):
    The air damper is fully serviceable and all parts are replaceable. We strongly recommend that this be done by a
    certified service center. However, if you have good wrenching skills, you can do this yourself (check the
    performance tuning section before doing this).
    Dropouts and Quick Release:
    This fork is made for QR15 hubs only and has a specific QR which is supplied with the fork and works with all
    QR15 front hubs that fit your fork. Wheel installation on an inverted fork can be a bit tricky compared to regular
    forks and requires attention. Before you insert the wheel, make sure both legs are at the same level and the
    dropouts are facing forward, this makes QR assembly easier.
    Warranty
    The original manufacturer warrants this fork for a period of two years from the date of purchase to be free from
    defects in materials or workmanship for the first owner only. During this warranty period we will replace or repair
    any defective component of the fork. Paint, anodizing or seal damage caused by normal use (“wear and tear”) are
    not covered by this warranty. We shall not be held liable for any damage caused by a crash, insufficient
    maintenance or ignorance of the safety and maintenance instructions. We shall not be held liable for normal
    maintenance, damage or failure due to abuse or misuse.
    Important Safety and Maintenance Instructions
    Warning:
    It is extremely important that your Wren Inverted Fork be installed correctly by a dealer. Incorrectly installed forks
    are dangerous and can result in loss of control of the bicycle and severe and/or fatal injuries. Follow the
    instructions below to avoid this. If you do not follow these instructions, your warranty will be void.
    Maintenance:
    To maintain safety, long life and high performance of your Wren Inverted Fork, periodic maintenance is required. If
    you frequently join competitions, ride in wet, muddy or other extreme conditions, a 50% reduction in
    recommended maintenance intervals listed below is necessary.
    1. After every ride clean and dry the exterior of your fork.
    Page 2
    ________________________________________
    Page 3
    2. Minimum every 25 hours of riding you should check the smoothness of your fork. The stanchions need to run
    smoothly up and down the seals. If they do not run smoothly, put 2-3 drops of a Teflon-based oil on the
    stanchions and move them up and down through the compression stroke (this is easier when you release
    some air pressure through the air valve).
    3. Check if all dials and nuts are still tightened properly.
    4. Check the stanchion tubes for scratches and also inspect the lower seals for any wear or tear. If one of the
    above mentioned parts appears damaged, do not ride and send your fork to a certified service center.
    5. After 100 hours of riding, your fork should be fully serviced by a certified service center. You may contact your
    dealer or Wren directly in order to find a certified service center.
    General instructions:
    1. This Wren fork is designed for off-road use. It is not designed for excessive riding like extreme jumps, etc. To
    use it on-road, you will have to follow your country’s specific traffic regulations and laws and equip your bike
    and your fork accordingly.
    2. Do not ride your bike if you notice technical problems or material failures like bending, cracking or broken
    parts. Immediately take your bike to a qualified dealer to prevent further damage. Failure to do this may result
    in damage and severe and/or fatal injury.
    3. Make sure the quick release lever is tightened and the hub axle is correctly fixed in the bore of the dropouts.
    When the quick release is locked, the lever should point backwards in the horizontal position on the post
    mount disc brake side of the fork.
    4. Adjust the headset until there is no play or drag.
    5. Install the brakes according to the manufacturers instructions and adjust brake pads properly. Use the fork
    only with brakes that fit to the existing brake mounts and use up to a 160 mm rotor. For larger rotors up to a
    maximum of 180 mm, use a proper post mount adapter for installation. Before riding the bicycle, ensure the
    brakes are properly installed and working properly.
    6. Do not add threads to the thread-less steerer tube.
    7. Do not replace the steerer tube by yourself as it needs to be pressed in under very high pressure.
    8. Do not disassemble the oil cartridge (right side leg) yourself. High pressure inside the cartridge may cause
    injuries and disassembly may lead to damage. Only an authorized service center should disassemble the oil
    cartridge. The air side of the fork may be disassembled in order to modify the fork’s travel in 10 mm
    increments. This is done by installing stoppers, sold separately. This may be needed to make sure that your
    tire does not hit the crown while the fork is fully compressed when using bigger volume tires. This must be
    checked properly before each first ride with a different tire width or height. Generally, the 135 mm hub fork can
    fit up to a 4” tire and the 150 mm hub fork can fit up to a 5” tire. Every rim tire combination can fit differently so
    you must check your travel and clearance. See page 7 for how to modify travel.
    9. Disassembly, maintenance and replacement of the oil damper must be made by an authorized service center.
    10. Avoid directing water pressure at the stanchions and/or seals.
    11. Be cautious when mounting the bicycle to a carrier. Carriers that hold the bike in trays with the wheels on are
    preferred. Follow the instructions of the carrier manufacturer. Avoid mounting the bike by fixing it at the
    dropouts (front wheel removed). The dropouts could be damaged.
    12. If your bike is transported by air, release the air pressure from the air spring side of the fork before packing.
    Deflating the air spring before transport avoids pressure damage and will guarantee proper function after
    transport.
    13. After a crash, have your bike and your fork inspected by a qualified dealer as internal damage may occur.
    14. Always use genuine Wren parts. Use of different parts voids the warranty and could cause structural failure of
    the fork resulting in loss of control of the bike with possible damage and/or injuries.
    Page 3
    ________________________________________
    Page 4

    Page 4
    Air Spring Insert
    Complete Fork Description
    Axle Nut
    Axle
    QR Lever
    Wren Inverted Suspension Fork
    QR15 Quick Release Axle
    Steerer Tube
    Red Air Spring Cap
    Blue Air Cap
    Crown
    Red Oil
    Damper Cap
    Oil Seals
    Stanchion Tubes
    Upper Legs
    Red Rebound Dial
    Right Dropout -
    Rebound Side
    Left Dropout -
    Brake Side
    Post Mount
    Brake Mount
    Blue
    Compression/
    Lockout Lever
    Serial Number
    Red Valve Cap - only
    on TwinAir forks
    Upper Assembly
    Cap Nut
    Air Valve
    Travel Clip
    (if installed)
    Bumper
    (various sizes)
    Air Spring Rod
    Stanchion
    Assembly Cap
    Air Piston
    Travel Limiter with
    Large Steel Spring
    Small Steel Spring
    ________________________________________
    Page 5
    AIR Spring Travel and AC Length Modifications
    Before your first ride you should check if you have enough tire to crown clearance. Depending on the
    model, this fork comes standard with either 100 mm (505 mm AC), 110 mm (530 mm AC) or 150 mm (570
    mm AC) of travel from the factory. If you are using narrow rims and big tires, you must check if you have
    enough clearance between your crown and tire before you ride with this fork. If you do not have enough
    clearance, the air spring needs to be modified with a clip(s) that will give you the proper clearance. Clips
    are now supplied with every fork. If you have an older fork, you may contact us to purchase clips. The
    clips reduce travel or travel and AC Length in 10 mm increments. As an example:
    150 mm of travel - pre-set at factory
    For 140 mm of travel - remove the pre-installed 10 mm clip and insert 1 - 20 mm clip.
    For 130 mm of travel - leave the 20 mm clip in place and add the 10 mm clip ABOVE the 20 mm clip. The 10 mm
    clip must always be on top.
    110 mm of travel - pre-set at the factory
    For 100 mm of travel - remove the pre-installed 10 mm clip and insert 1 - 20 mm clip.
    For 90 mm of travel - leave the 20 mm clip in place and add the 10 mm clip ABOVE. The 10 mm clip must be on
    top.
    100 mm of travel - pre-set at the factory
    For 90 mm of travel - remove the pre-installed 10 mm clip and insert 1 - 20 mm clip.
    For 80 mm of travel - leave the 20 mm clip in place and add the 10 mm clip ABOVE. The 10 mm clip must be on
    top.
    Checking for Crown to Tire Clearance:
    1. Install the front wheel on the fork being sure tire is properly inflated.
    2. Release air from the air spring to make fork easier to compress.
    3. Push down on the handlebars until the fork bottoms out and check for the amount of clearance between crown
    and tire. A minimum of 5 mm is recommended.
    Air Spring Travel Modification and Assembly:
    1. Place your bike in a work stand and remove the front wheel.
    2. Remove the blue air cap from the left leg and release all the air from the system. If your fork is a TwinAir, be
    sure to empty both top and bottom air chambers.
    3. Loosen and carefully remove the air spring assembly cap (large silver nut below the blue air cap) with a 26
    mm socket. DO NOT remove the red air spring assembly cap.
    4. Unscrew the seals from the stanchions by hand. Now the air spring can be pulled out including the air side
    stanchion from the bottom of the fork.
    Warning: At this stage please absolutely make sure again that all the air has been released from the air
    spring unit to avoid severe and/or fatal injuries.
    5. Select the correct stopper(s) as discussed above.
    6. Insert the proper stopper size into the air spring at the top directly below the upper assembly cap and onto the
    flattened sides of the rod. For a 10 mm stopper, snap onto the rod and slide up over the flattened surfaces of
    the upper assembly cap. For the 20 mm stopper, be sure the wide-mouth end is at the top, facing up. This end
    is chamfered to fit over the flattened surfaces. Lineup with the flattened surfaces and snap onto the rod. If
    using both stoppers, be sure the 10 mm is on top.
    7. Reverse steps 1 to 4 for reassembly. Be sure to torque the air spring assembly cap to 10Nm. Be sure the fork
    seals are hand tight. Be sure to check your air pressure and sag.
    Page 5
    ________________________________________
    Page 6
    Air Spring Travel and AC Length Modification and Assembly:
    You can reduce travel and the AC Length of the fork by placing the travel clips INSIDE the air spring.
    1. Follow steps 1 through 4 above to remove the stanchion with the air spring from the fork. Be sure ALL air is
    released from the air spring.
    2. Looking at the top of the air spring, you will see a silver cap with 2 holes. This is the stanchion assembly cap.
    Using a pair of bent nose pliers in the holes, unscrew the cap completely.
    3. Grip the top of the air spring firmly and pull it out of the stanchion. This may take some effort.
    4. Locate the Small Steel Spring at the bottom of the air spring. The clips will be installed on TOP of that spring
    and below the white plastic bumper above that spring. The clips snap onto the rod same as above.
    5. If only one clip is used, it must be the 20 mm clip because it is designed to rest on the spring. Remember that
    the wide-mouth side of the 20 mm clip must face up. The 10 mm clip should only be used with the 20 mm clip
    and must be installed on TOP of the 20 mm clip.
    6. Be sure the Large Steel Spring is well greased. All coils should be “filled” with grease. If riding in cold
    weather, be sure to use a grease specified for use in the temperature you will be riding in.
    7. Lightly grease the air piston seals and insert the air spring back into the stanchion. CAREFULLY thread the
    stanchion assembly cap back into the stanchion making sure not to cross thread the cap. Tighten securely
    with the bent nose pliers.
    8. Now reverse steps 1 to 4 from the travel modification section and install the stanchion into the fork. Be sure to
    check your air pressure and sag.
    Fork Setup/Performance Tuning
    Please follow these instructions if you want to modify the ride or feel of this fork. For additional information, please
    ask your dealer or contact Wren directly.
    After installing the fork on your bike correctly, you must determine the correct fork setup for your weight and riding
    style. First step is to inflate the fork because the fork is shipped with less air than you need to ride (air freight
    requires forks at very low or no air pressure). Remember, the following is a guide. The final settings are
    determined by paying attention to the feel of the fork and adjusting over your first few rides.
    Air Spring - TwinAir
    If your fork is equipped with an air valve on the bottom of the Air side (left) leg, you have a TwinAir fork. This fork
    has air valves top and bottom under protective caps. Begin by filling both chambers with 30psi as a STARTING
    point to set your sag (see below). Adjusting the pressure up or down in the top or bottom chamber affects slow
    speed compression. This can help smooth out the small stuff. Once sag is set, increasing air in the top chamber
    will give the fork a plusher feel, increasing air in the bottom chamber gives the fork a stiffer feel. The only way you
    will know for sure how it affects your ride is to play with it on your first few rides. Maximum air pressure is
    120psi.
    Air Spring - Single Air
    If you have a single air valve on top of the left leg, you have a single air fork. Remove the blue air valve cap and
    use a suspension pump to pump up the fork to 30 psi as a starting point. Push down on the fork a few times to
    determine if it feels about right for you. Adjust pressure if necessary. Maximum air pressure is 120psi. Now
    check for the proper sag.
    Fork Sag Setup:
    Sag is the amount of travel that is used when a rider sits on the bike and the suspension compresses under the
    rider’s weight. Sag, also known as negative travel, is needed to achieve a well-functioning fork. Sag on this fork
    should be around 20% of the fork’s travel. This can be easily measured by first locating the rubber o-rings on the
    stanchion tubes. Be sure no one is on the bike and the fork is uncompressed. Slide the o-rings up against the
    seals. Now carefully sit on the bike in your riding position with all your gear and let your weight slowly compress
    the fork. Do not bounce the fork. Carefully dismount being sure not to compress the fork. Now measure the
    distance between the o-rings and the seals. If the distance for the 110mm travel fork is around 22mm, your
    starting sag setup is good. If the distance is less than 22 mm, reduce the air pressure in the air spring. If the
    distance is more than 22 mm, increase the air pressure in the air spring. Remember, for a TwinAir fork add or
    decrease pressure equally when setting your sag. This is now your starting point. Adjustments from here need to
    be done as you ride and feel out your new fork.
    Page 6
    ________________________________________
    Page 7
    Rebound Knob:
    The rebound speed of the hydraulic damper can be fine-tuned by turning the external red knob at the bottom of
    the right leg. Turn the knob clockwise for slower rebound. Slower rebound means that the outward movement of
    the fork after compression is slower (the damping is higher). Turn the knob counter-clockwise for faster rebound.
    Faster rebound brings the fork back to its original position faster. For bumpy rides, we recommend a fast setting to
    avoid over-damping. To start, try setting the Rebound knob to the middle setting.
    Do not turn the rebound knob past its limits. Squishy sounds in the sealed rebound stages are normal, it’s just the
    oil flowing back into the compression stage of the cartridge. This means your fork works! If you choose a faster
    rebound setting, the squishy noise will lessen and the fork will bounce back to its extended position faster, but the
    damping will become less.
    Lockout / Compression Adjustment Lever:
    In addition to the rebound adjustment, the fork can be completely locked out from compression by the lockout
    system. Just turn the blue lockout lever clockwise until its limit to lock out the fork (do not move past this limit). We
    recommend this when climbing uphill or when no front suspension is needed. A very slight inward movement of
    the fork may appear even when the lockout is activated. This is required to avoid damage to the cartridge and the
    fork. To unlock the lockout function, turn the lockout lever counter-clockwise (do not move past the fully open
    limit).
    In between the two limits (fully open / locked) is the compression adjustment range.
    The compression becomes firmer when the lever is turned clockwise toward the lockout and softer when turned
    counter-clockwise toward the fully open position.
    First Ride
    It is advised to ride the fork on a flat surface at first in order to make any adjustments necessary to achieve the
    ride you want. A new fork will have slight seal friction. Seals and stanchions need to break in and after a few hours
    of riding the fork will move up and down smoother. If this changes the feeling you want, simply readjust your
    settings. On your first off-road ride, it is advised to bring a suspension pump in order to be able to make additional
    adjustments if needed.
    Thank you for purchasing the Wren Inverted Suspension Fork. To see other fine Wren products, please visit
    www.wrensports.com. Should you ever have any questions, comments or just need more information, please
    contact us at:
    WREN SPORTS, LLC
    106 Camino Del Sol, Vallejo, CA 94591
    707-652-2737
    www.wrensports.com

    Page 7
    ________________________________________
    Wren 150mm Tuning/Setup Guide-wren-3.jpg


    => If anyone wants the PDF, send me a PM with your email and I'll reply with the attachment.

  40. #40
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    That is awesome! Then this fork is a Clear Winner of Fat Bike forks. Will try to lower Down to 140mm AC, to see if that fits the Foes Mutz better. Now it is a bit hig in the front, when climbing. There is so easy to open and take out air damper that you will only use 15 minutes to put in the Clips. I will also get a New compression damper, though the original Works, but it is a bit tricky to adjust sinci it is really progressive the last 4mm of the adjustment knob. Starting to love the feel of these fork now, and I am getting hold of the air pressure adjustment also. Running 55psi in both Chambers. Before I used a 150mm travel Pike on my skinny FS, I would say the Wren fork is more rigid and stiff then the pike.

  41. #41
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    Quote Originally Posted by JCHKeys View Post
    So I mounted up my Wren and did the first test right last night. There is definitely a loose feel, but side by side with my other fat bike with a Bluto, doing the simple test of holding the front wheel with my knees and turning the handlebars, there was a difference. The wren had a very loose feeling for about 3/4 inch turn of the handlebars, but then became solid and wouldn't move any more. The bluto felt like a wet noodle where I could put more force and keep twisting the handlebars.

    So are the Wren doesn't have as much breaking twist as the Bluto, but this has only been street riding as my trails still have a foot of snow on them.

    Has anyone gotten their fork back from any servicing by Wren or Hippie Tech? Were they able to fix this looseness?

    Oh and when I dumped out the Wren box, two awesome clamps for the carbon guards dropped out, so much nicer than my hokie zip ties.
    I can not see any reason to bother with the loosness feel of twisting the fork between Your hands and legs since The fork is as stiff and rigid as a dual Crown fork when riding it!!!

  42. #42
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    Its a simple and easy test to check the overall stiffness of the front end of a bike. I do the bikes in my stables and other peoples bikes in my club, and sometimes its amazing. Example, I got one of the first 130mm travel Fox Floats back in 2004ish. I took off a 20mm Sherman fork to put this fox on; whereas the Sherman had maybe 1/2 to 3/4 inch movement at the handlebar, the QR Fox had a solid 1.5-2 inch movement... and it showed on the trail. This test also quickly shows you if its fork, hub, or rim by looking down and seeing what moves. This has lead to countless hub repairs and spoke tightenings...

  43. #43
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    Quote Originally Posted by JCHKeys View Post
    Its a simple and easy test to check the overall stiffness of the front end of a bike. I do the bikes in my stables and other peoples bikes in my club, and sometimes its amazing. Example, I got one of the first 130mm travel Fox Floats back in 2004ish. I took off a 20mm Sherman fork to put this fox on; whereas the Sherman had maybe 1/2 to 3/4 inch movement at the handlebar, the QR Fox had a solid 1.5-2 inch movement... and it showed on the trail. This test also quickly shows you if its fork, hub, or rim by looking down and seeing what moves. This has lead to countless hub repairs and spoke tightenings...
    I was also observing the same when checking the fork like you tell me, but when riding the fork, it feels as stiff and rigid as the Rock Shocks Pike in 29er 150mm, so what is the problem then? When is it likeliy to believe Your Wheel is put up to forces like this? When do you put Your Wheel between two tree legs and twist the handlebar at the same time?? Or when do you Place Your Wheel into mud or rock that Locks Your Wheel sideways like you are doing? If the Wheel is locked With a 15mm axle to the fork, why should the hub or spokes be affected by these kind of forces? Why should it be possible to run a cannondale fork With one leg then, since that is not supposed to be stiff or rigid at all, and should destroy hubs and spokes like nothing else?

  44. #44
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    My fork was replaced by the factory last week. They didn't have time to pull it apart and diagnose the issues I was experiencing, which is kind of a bummer. I like having answers.

    But I also like having a fork that works as advertised, and the replacement feels great after one short ride. Suiting up to take the long, trail-version of my commute into work right now, at 6*f, which should be a good test of the cold weather oil and grease they're using.

    One thing I'm not at all clear on is how to use the top and bottom air chambers to tune the fork. Russ gave me a verbal answer to this but it wasn't very clear, and the fiddling I've done (on the old, bad fork) achieved nothing of note other than to take the fork from feeling like crap to feeling like rigid.

  45. #45
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    How's the rebound?

    Is it still too damp?

    Does it feel like it's slow to return?

    I tried using higher pressure in the lower and low pressure in the upper, this made it more supple but rebound is still slow; damper?

    When I play with the new uninstalled damper, twisting the rod that attaches to the damper adjuster in the lower leg, I don't notice much difference in how the damping effect changes...

    Quote Originally Posted by mikesee View Post
    My fork was replaced by the factory last week. They didn't have time to pull it apart and diagnose the issues I was experiencing, which is kind of a bummer. I like having answers.

    But I also like having a fork that works as advertised, and the replacement feels great after one short ride. Suiting up to take the long, trail-version of my commute into work right now, at 6*f, which should be a good test of the cold weather oil and grease they're using.

    One thing I'm not at all clear on is how to use the top and bottom air chambers to tune the fork. Russ gave me a verbal answer to this but it wasn't very clear, and the fiddling I've done (on the old, bad fork) achieved nothing of note other than to take the fork from feeling like crap to feeling like rigid.

  46. #46
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    Quote Originally Posted by Rumblefish2010 View Post
    When do you put Your Wheel between two tree legs and twist the handlebar at the same time??
    Pretty much any time you ride through technical terrain and want the bike to follow your steering inputs and not what the rocks are trying to deflect the wheel towards. As a long time user of several inverted single crown forks, this was usually the worst thing about them. Off-camber or through serious rock tech sections you puckered up big time, because the fork had a tendency to go where it wanted because of that torsional play/lack of rigidity.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  47. #47
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    Quote Originally Posted by Nurse Ben View Post
    How's the rebound?

    Is it still too damp?

    Does it feel like it's slow to return?

    I tried using higher pressure in the lower and low pressure in the upper, this made it more supple but rebound is still slow; damper?

    When I play with the new uninstalled damper, twisting the rod that attaches to the damper adjuster in the lower leg, I don't notice much difference in how the damping effect changes...

    Normal rideable range now. Pogo stick on one end, then twist the knob to the other end and it's slow as molasses.

  48. #48
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    That's not a problem with the Wren, I ran it through a wet rocky line and it tracked like a fork should track, it went where I pointed it, and it didn't twist or veer off line.

    If I didn't know it was an inverted fork, I wouldn't know it was an inverted fork by the way it handles.

    Quote Originally Posted by Jayem View Post
    Pretty much any time you ride through technical terrain and want the bike to follow your steering inputs and not what the rocks are trying to deflect the wheel towards. As a long time user of several inverted single crown forks, this was usually the worst thing about them. Off-camber or through serious rock tech sections you puckered up big time, because the fork had a tendency to go where it wanted because of that torsional play/lack of rigidity.

  49. #49
    since 4/10/2009
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    I'm liking what I'm reading in these recent reports.

  50. #50
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    Quote Originally Posted by mikesee View Post
    Normal rideable range now. Pogo stick on one end, then twist the knob to the other end and it's slow as molasses.
    That was good to hear, I will also get a New oil damper, lets hope that will work out as well. ¨

    I think you kan approach the air filling starting With putting 50 PSI on the bottom Chamber first and the same in the top Chamber. Then you start to add air in the top Chamber, to get the sag correct. When you get the sag correct, you can add or remove air in the bottom Chamber to get the bottom out resistance you want to have. Note that you will have the exact same air pressure in the bottom Chamber you ended up With when you found the correct sag. Since the air pressure is balancing between the two Chambers. Since there is a plunge that is moving according to the pressure you will shrink the top Chamber likewise. You can think about the bottom Chamber like an adjustable bottomless token. It will give you really good adjustable bottom out resistance. The way is to forget the air pressure measurement, only adding or lowering one amount of pressure. I have also noted the feel of the fork is more progressive With more air in the bottom Chamber.

  51. #51
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    Quote Originally Posted by Nurse Ben View Post
    That's not a problem with the Wren, I ran it through a wet rocky line and it tracked like a fork should track, it went where I pointed it, and it didn't twist or veer off line.

    If I didn't know it was an inverted fork, I wouldn't know it was an inverted fork by the way it handles.
    I can confirm the same, running these fork in 1-2 month without snow. I have had several forks, non inverted, that is not holding the line like the Wren. Neither of them have been so plush either.

  52. #52
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    Bit of an update.

    My rides thus far on the Wren have been largely on snow, with some ice, mud, and icemudruts mixed in. Not the best terrain to test chassis stiffness, nor the worst.

    That said, part of my commute is a fairly steep bit of tarmac, which I often use to bed in brakes. In this case I've used it to lay on said (front) brake to see if I can feel or literally see any chassis deflection. And compared to the other forks that I ride on a daily basis, there isn't anything I can feel or see. No flex, no twist, nothing.

    Damper quality feels great when it's warm. No detectable stiction. No odd quirks, nothing out of what I consider ordinary. It feels good.

    The sole remaining question, for me, is solving the sluggish-when-cold issue. Is the oil too thick? Maybe. Is the grease on the air spring too thick? Maybe. I made a point of telling Russ @ Wren the temps that I ride in, and it's right there on their website that this fork has been tested/approved to -51*f.

    Clearly it isn't approaching that level of performance as yet, despite the fact that Russ said the factory installed a grease specific to the temps I ride in. I've been very direct with Russ that I want to solve this, and he has been communicative but hasn't provided a clear answer yet. I think this is because Wren is more of a distributor/importer than a suspension house. They just don't have the experience to know what the answer is, so they have to cast about to find it.

    That's all well and good in the prototype and preproduction phase, but it chaps me pretty good that they are effectively using the first batch of buyers to sort things out. If the fork was free and I was being compensated for the time spent to sort things out, then fine. But I paid for this fork, and despite the fact that it has been replaced and (allegedly?) tuned for the temps I encounter daily, it is still falling short.

    The ball is in Wren's court on this one. I hope they don't drop it.

  53. #53
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    It seems like the chassis is pretty good in terms of stiffness, but you're still having issues with the low temperatures (I'm guessing it may be the damper).
    I really want to pull the trigger on this fork, but for $900 I expect this thing to be dialed.

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  54. #54
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    Quote Originally Posted by rollertoaster View Post
    It seems like the chassis is pretty good in terms of stiffness, but you're still having issues with the low temperatures (I'm guessing it may be the damper).
    I really want to pull the trigger on this fork, but for $900 I expect this thing to be dialed.

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    Agreed that it should be dialed.

    The chassis has a quirk, unique to it compared to any other USD fork I've owned or ridden: If you stand over the bike and lock the front brake, then rock the bike forward and back as though checking for a loose headset, you can feel a slight knock. It feels like a loose headset. It isn't. Nor is it the brake rotor moving on the hub, nor the pads in the caliper. It's the lowers, moving independently of the uppers. It might even be the sliders hitting the edges of the keyways, though I haven't pulled it apart to verify the exact source. What is certain is that you can feel it when you're standing over the bike and rocking it in place.

    I cannot feel it, not in any way, when riding, simply because when riding I'm moving forward and the fork is always loaded against forward movement. If you were/are a trials guy, stopping and pivoting and hopping and such, you *might* be able to feel it. Does it change anything if you *can* feel it when riding? I doubt it, but that's speculation because I simply can't feel it when riding, so I can't say for sure.

    If I can get the sluggish-when-cold answer, and change it, I'll be happy with the $$$ spent.

  55. #55
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    I would wager the knock is in the keyways or bushings. But as long as it's not noticeable when riding (including manualling or pulling the front wheel up) that wouldn't be a deal breaker.

    I too would definitely require cold weather performance. Hell my ideal conditions are around 20f when the ground is frozen solid and dirt grips like a blanket of velcro.

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    I know what Mike is feeling, it worried me when I bench tested the fork, but on the bike it's rock solid. I don't feel any knocking or movements when flipping the front end around, unlike the Bluto which had a clunk when lifted fast.

    Had to remodel a remodel, the wall looks good, but I didn't play bike mechanic, maybe Fri or early Sat.

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    There is a play in the key and keyways and I think it need to be, to get low friction. But I have never felt these when riding. The fork is sluggish when new, but after 3 weeks of use, mine is good. It might be the Austrian RSP Slick Kick grease they use, and it seems to be overdoing the use of grease. It also might be the key braking in doing the sluggish feel? I have had no problems with my fork in low temp as 0 Fahrenheit. The thing is that the oil needs to be warm by the ride. When commuting with my bike to work the oil never gets working temperature. These is also remarkable with my rear shocks. I used a Cane Creek DB Air until that gave up in the cold, and now I am using a Fox. Both is not getting working temp. When commuting in cold weather.

  58. #58
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    Okay, so I had a couple hours at lunch to tear down my Wren:

    The Air Side:

    First things first, it is easy to add the clips, just undue the 26mm silver nut on the top of the air side leg, unscrew the seal by hand at the bottom of air side leg, pull out the stanchion, then change add clips at the top of the air shaft to change travel.

    If you want to change travel and A-C, then you need to take the next step and remove the silver threaded plug at the top of the air shaft to access the lower air shaft spring, which is where the clips can be added.

    So, the instructions say that the 20mm clip must be added before the 10mm clip can be added, whcih means the fork can be reduce to 130mm or 120mm, but not 140mm. I called and left a message for Russ to clarify, but that seems to be the case. So I reassembled the air side after wiping off some excess grease.

    Next the damper side:

    This is also a much easier process with a closed bath system than an open bath because the oil is contained within the bladder, or at least it's supposed to be... mine was filling the leg! Yup, as Russ suggested, my Damper was defective, somehow the adjustment shaft had become loosened or was not properly attached inside the bladder, so all the oil had leaked into he leg which explains why I had no adjustment in damping and why it was so "boggy".

    After cleaning out the leg I change dampers, and put it back together.

    All told, if I was going to rebuild a Wren, changing seals and relubing, I could do it in thirty minutes in the back of my van, seriously, it is just too easy.

    No ride impressions yet, but I'll report back later after a ride or two.

    Here are some pics I took as I went, note bronze colored keyways, there is one on either side of both stanchions

    Air side stanchion removed, air shaft still installed. For travel reduction ONLY, clips go between yellow washer and existing black spacer.
    Wren 150mm Tuning/Setup Guide-20160205_125652_resized.jpg

    Air side stanchion, silver nut undone, air shaft still in stanchion
    Wren 150mm Tuning/Setup Guide-20160205_130122_resized.jpg

    Air shaft removed from stanchion. Spacer placement to reduce A-C is at base of spring
    Wren 150mm Tuning/Setup Guide-20160205_130320_resized.jpg

    LEFT old Damper (notice missing adjustment rod), RIGHT new damper
    Wren 150mm Tuning/Setup Guide-20160205_133146_resized.jpg

    Damper side stanchion removed, damper still in stanchion.
    Wren 150mm Tuning/Setup Guide-20160205_133232_resized.jpg

    Damping adjustment knob removed to access damper adjustment rod connecting nut
    Wren 150mm Tuning/Setup Guide-20160205_133526_resized.jpg

    Old damper rod, notice it's not connected to the damper (that's why my damping was shite). Ignore the new damper in the stanchion, I was just checking fit before install; damper installs from above, then it's attached to the adjuster after the stanchion is reinserted in the leg.
    Wren 150mm Tuning/Setup Guide-20160205_134059_resized.jpg

  59. #59
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    I'm glad it's simple to service, inverted forks usually are. By any chance are you going dive into that defective damper? I'm curious if it is user tune able.

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    Edit: Disregard the previous contents of this message, it was user error, I didn't have the knob secure, the tiny allen screw was not in the dimple, so it spun free.

    I had a snack, thought about it, looked at it, fixed it, life is good!

    And yeah, I'm happy with how the fork feels, now to install my JJs and go ride!!

    Thanks to Russ at Wren.

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    I'll see if I can get it open.

    The fork is a modular design, so the damper is designed to be replaced as a unit.

    Quote Originally Posted by rollertoaster View Post
    I'm glad it's simple to service, inverted forks usually are. By any chance are you going dive into that defective damper? I'm curious if it is user tune able.

    Sent from my SAMSUNG-SM-N910A using Tapatalk

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    Two business days since I sent Russ a request for info about the sluggishness of my fork at cold temps. No response going into the weekend.

    Finished my commute home tonight on a mix of snow and frozen mud and ice-packed trails, thermograph read 13* when I rolled into the garage. Flipped the bike upside down and removed the wheel, so that I could cycle each leg independently to determine if the sluggishness was air side or damping side. Felt like damping side, especially on the rebound.

    Thus I'm curious, and have looked at Ben's pics but don't see the answer: Can I simply change to a lighter oil in the damper? Or is the damper 'sealed' in such a way that it is unserviceable?

  63. #63
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    I'll see if it will open, but after getting a first hand (and floor) look at the oil, I'm not sure you could go much lighter. It was maybe 10wt, greenish color.

    You'd need to know more about oil volume, wt would be a guess, though I suppose you could try to measure it. It was not a lot of oil. My wife just went to bed, so I'll go try to open it.

    Is there any possibility the damper is not opening all the way?

    On the air side, there was a fair amount of grease, but nothing crazy and it's much less sticky than the red stuff SRAM uses.

    Now that the damper works, I have it set about 2 turns in; there are 4.5 turns possible, and it's quite responsive.

    Quote Originally Posted by mikesee View Post
    Two business days since I sent Russ a request for info about the sluggishness of my fork at cold temps. No response going into the weekend.

    Finished my commute home tonight on a mix of snow and frozen mud and ice-packed trails, thermograph read 13* when I rolled into the garage. Flipped the bike upside down and removed the wheel, so that I could cycle each leg independently to determine if the sluggishness was air side or damping side. Felt like damping side, especially on the rebound.

    Thus I'm curious, and have looked at Ben's pics but don't see the answer: Can I simply change to a lighter oil in the damper? Or is the damper 'sealed' in such a way that it is unserviceable?

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    Mike, check your email, I sent pics of the damper dissasembled.

    Changing oil is doable, might need to have an o ring handy as the one that was installed on the top cap was kinda brittle.

    My damper failed because the plunger came unscrewed from the adjusting rod, it probably could use some loctite during factory assembling.

    Pretty simple fork.

    I did a little ride around the block, nothing serious, but it felt good, nice and supple, no weirdness, responsive.

    And those JJs, what a difference compared to Floaters, 200+ gm weight savings and the beads pop up true on the rim; the Floaters were all kinds of wobbly.

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    They use Damp Champ 2.5 wt oil. From R.S.P.

  66. #66
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    Quote Originally Posted by Nurse Ben View Post
    Mike, check your email, I sent pics of the damper dissasembled.

    Changing oil is doable, might need to have an o ring handy as the one that was installed on the top cap was kinda brittle.

    My damper failed because the plunger came unscrewed from the adjusting rod, it probably could use some loctite during factory assembling.

    Pretty simple fork.

    I did a little ride around the block, nothing serious, but it felt good, nice and supple, no weirdness, responsive.

    And those JJs, what a difference compared to Floaters, 200+ gm weight savings and the beads pop up true on the rim; the Floaters were all kinds of wobbly.
    If the damper uses a bladder you don't necessarily need to know the oil volume you just need to get it full and get all the bubbles out. Have you ever service a pike? there is a special tool required to pull vacuum on the damper and pull all the bubbles out.

    I know the damper uses a light oil but hopefully it will be possible to modify the rebound circuit to make it faster for those who feel it's sluggish

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    I'm not a suspension pro, but looking at the parts, I'd say it could easilly be modified, but you'd want a few spares...cuz there would be mistakes

    Once he gets up, maybe Mike can post my pics.

    Wakey, wakey

    Quote Originally Posted by rollertoaster View Post
    If the damper uses a bladder you don't necessarily need to know the oil volume you just need to get it full and get all the bubbles out. Have you ever service a pike? there is a special tool required to pull vacuum on the damper and pull all the bubbles out.

    I know the damper uses a light oil but hopefully it will be possible to modify the rebound circuit to make it faster for those who feel it's sluggish

    Sent from my SAMSUNG-SM-N910A using Tapatalk

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    I wasn't able to find the viscosity values at 40c and 100c for RSP oils, but I did find a chart that compared a large variety of well known shock/fork oils and Redline "Like water" is a ~ 2.5wt that seems to maintain the most consistent viscosity across the temperature range.

    Red Line Synthetic Oil - Suspension Fluids - LikeWater® Suspension Fluid.

    So Mike, I'm going to ask Russ if it's alright to send you the damper before it goes back to Wren; perhaps they don't even want it.

    Let me know if you want it


    Quote Originally Posted by Rumblefish2010 View Post
    They use Damp Champ 2.5 wt oil. From R.S.P.

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    I do not see why you need to change oil, and why you need to modify the compression unit? The oil should be thin enough and if you got an adjustable new compression unit, working like it should both in rebound and compression adjustment, please let it be used for a while to break in. Also look at the inner stanchions to see if it is coated With grease. Cleaning the stanchions makes a big difference and makes the fork really smooth. So use generous amount of fork spray like MucOff Silicon spray or something suitable. First clean off the layer of grease and then lubricate the stanchions. These was even more important in Cold weather when the grease coat was even more sticky. It is also necessary to do these maintance, after some hours of use. I also found the grease sticking even more before the seals where broken in.
    Last edited by Rumblefish2010; 02-06-2016 at 01:34 PM.

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    Quote Originally Posted by Rumblefish2010 View Post
    I do not see why you need to change oil, and why you need to modify the compression unit? The oil should be thin enough and if you got an adjustable new compression unit, working like it should both in rebound and compression adjustment, please let it be used for a while to break in. Also look at the inner stanchions to see if it is coated With grease. Cleaning the stanchions makes a big difference and makes the fork really smooth. So use generous amount of fork spray like MucOff Silicon spray or something suitable. First clean off the layer of grease and then lubricate the stanchions. These was even more important in Cold weather when the grease coat was even more sticky. It is also necessary to do these maintance, after some hours of use. I also found the grease sticking even more before the seals where broken in.
    You have no fooking clue who you're talking to like a noob, do you?

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    Quote Originally Posted by Rumblefish2010 View Post
    I do not see why you need to change oil, and why you need to modify the compression unit? The oil should be thin enough and if you got an adjustable new compression unit, working like it should both in rebound and compression adjustment, please let it be used for a while to break in. Also look at the inner stanchions to see if it is coated With grease. Cleaning the stanchions makes a big difference and makes the fork really smooth. So use generous amount of fork spray like MucOff Silicon spray or something suitable. First clean off the layer of grease and then lubricate the stanchions. These was even more important in Cold weather when the grease coat was even more sticky. It is also necessary to do these maintance, after some hours of use. I also found the grease sticking even more before the seals where broken in.
    My fork feels great indoors, at ~65*. It feels terrible when frozen, under 32*.

    In order to solve this conundrum something needs to change. Riding it for 3 weeks while whistling zippity do da might have worked for you, but isn't a "solution" to me. Changing oil is a quick way to change a lot about a fork. If it doesn't solve the problem, at least I can then rule it out and move onto the next.

    You sound like a shill, or dangerously close to David Cop-a-feel. That said, your engrish is likely worlds better than my ability to speak your native tongue.

  72. #72
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    Quote Originally Posted by Nurse Ben View Post
    I wasn't able to find the viscosity values at 40c and 100c for RSP oils, but I did find a chart that compared a large variety of well known shock/fork oils and Redline "Like water" is a ~ 2.5wt that seems to maintain the most consistent viscosity across the temperature range.

    Red Line Synthetic Oil - Suspension Fluids - LikeWater® Suspension Fluid.

    So Mike, I'm going to ask Russ if it's alright to send you the damper before it goes back to Wren; perhaps they don't even want it.

    Let me know if you want it
    Yep, that'd be great.

    I have a decent amount of experience with fork oils, and one company's 2.5wt can be equivalent to someone else's 10wt.

    I'll have to dig out my stash of oils and refamiliarize myself with the cold temp leader. If ever in doubt, stick 'em in the freezer for a few hours, then when you remove them, simply pour both into a vessel and you can usually *see* the difference. One of the more popular bicycle fork oils wouldn't pour at all -- like frozen honey -- when I did this 'test', while the same claimed weight moto oil flowed out like it was +70*.

  73. #73
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    Quote Originally Posted by rollertoaster View Post
    If the damper uses a bladder you don't necessarily need to know the oil volume you just need to get it full and get all the bubbles out. Have you ever service a pike? there is a special tool required to pull vacuum on the damper and pull all the bubbles out.

    I know the damper uses a light oil but hopefully it will be possible to modify the rebound circuit to make it faster for those who feel it's sluggish

    Sent from my SAMSUNG-SM-N910A using Tapatalk
    I like really, really fast rebound. Virtually zero damping, so that I can use that rebound speed to keep the front end light and load it up to pop off of things.

    The Wren is one of the few forks I've ever owned where I have to run some rebound damping, because with it all the way open it's just too fast.

    Until it's frozen, that is.

  74. #74
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    Mike, it'd be worthwhile to tear down the air side and take out the extra grease. Not a perfect fix, as you said, it's the damper that seems to be slowing things down.

    I'll send the damper.


    Quote Originally Posted by mikesee View Post
    I like really, really fast rebound. Virtually zero damping, so that I can use that rebound speed to keep the front end light and load it up to pop off of things.

    The Wren is one of the few forks I've ever owned where I have to run some rebound damping, because with it all the way open it's just too fast.

    Until it's frozen, that is.

  75. #75
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    Quote Originally Posted by mikesee View Post
    My fork feels great indoors, at ~65*. It feels terrible when frozen, under 32*.

    In order to solve this conundrum something needs to change. Riding it for 3 weeks while whistling zippity do da might have worked for you, but isn't a "solution" to me. Changing oil is a quick way to change a lot about a fork. If it doesn't solve the problem, at least I can then rule it out and move onto the next.

    You sound like a shill, or dangerously close to David Cop-a-feel. That said, your engrish is likely worlds better than my ability to speak your native tongue.
    What?? Is my language used too undermine my user experience of the Wren Fork? Yes, I am not a Pro user or a pro bike mechanic….and I have never said it. I only want to bring all relevant information to the table here, and I am an average user not a pro! I still not agree that the fork change dramatically in behaviour before it comes down to 15 Fahrenheit. Mine is just perfect at 32. As long as I change the rebound and the air pressure when the temperature drops, and for sure I do need to do that when it is 15 Fahrenheit. I cannot think these is unormal when Comparing to my rear shocks and to other forks like the Bluto, these is more normal. My only complaint is the adjusting of the compression unit is only working in the last 5mm of the knob travel. The only modification I have done, is to put in a New air spring using a different kind of grease and less grease. I have used Rock'n Roll Super Slick. There should also be mentioned that I got a New air spring due to a mistake. I thought something was wrong and Russ sent me a New air spring. When filling air to the shock I thought something was wrong, since I thought air was leaking from top Chamber to the bottom Chamber. Until I found out by the drawings of the fork, how the air Chambers worked, I thought it where leaking air between them.

  76. #76
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    Quote Originally Posted by Rumblefish2010 View Post
    I still not agree that the fork change dramatically in behaviour before it comes down to 15 Fahrenheit.
    I'm not asking you to agree with my summary of my fork's behavior. I'm 100% certain I can do that accurately on my own.

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    First "serious ride" today on the Wren, mix of mud, snow, rock, firm dirt, did my standard loop at Ancient Lakes, then did multiple repeats on a 1/2 mile techy/flow section to dial in the air pressure (60/60).

    Then I headed down a rocky gulley littered with drops, baby heads, scree, snow, etc... this part of the trail is pretty tight, steep, and I routinely hurt myself in there

    Anyway, it was a good test of the Wren and a place I rode often with the Mutz/Bluto combo. Going down was scary due to loose conditions and rock fall, but the Mutz motored through, no dabs which is uncommon considering.

    Climbing back out led to a few crashes, mostly low speed, high centers, wash outs, but I did get the chance to work over tough lines.

    All in all, it was a solid afternoon of riding, really the hardest I work a fork other than going to a bike park, and the Wren killed it

    Seriously, since the damper was replaced, the fork is solid, very plush, damper works, lockout works, no wonkiness, no looseness. In other words, two preliminary thumbs up.

    Only preliminary because it's a new fork, so a year from now pending continued performance without breakdowns, it'll keep the thumbs.

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    Quote Originally Posted by mikesee View Post
    I'm not asking you to agree with my summary of my fork's behavior. I'm 100% certain I can do that accurately on my own.
    Of course, I am not asking you to agree either, just my bad English. I am only talking about my fork and mine experience....

  79. #79
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    One of the things that fork mfgs need to consider is that many end users do want the option of adjusting fork performance. Having a proprietary closed damper system may be good in some ways, but it certainly limits end user tinkering; this was suggested in Russ's exchanges previously where the factory was saying "no" to user repairs.

    Having pulled apart the damper, I have no doubt it can be modified, though with Wren already using a very low viscosity oil, it makes it more challenging to improve cold weather performance.

    I'd like to see Wren modify the damper so that it works similarly with a higher weight (5wt) oil, then it would be a simple matter to change to a lower wt oil.

    I'm not a fork oil expert, but in my research, looking at oils that work best in low temps, there are only a few that perform better than what Wren is already using.

    That said, my fork worked flawlessly last night at freezing, no change in damper performance going from 45f to 30f, of course that's not really a good test for a winter use fork, but hey, it's all I got right now

    I will admit that changing air pressure and adjusting damping as temperatures change, that is to be expected, but the range of adjustment needs to fall within the range of likely use, say -20F to 120F, or so.

  80. #80
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    Wren damper pics:

    Top cap, unscrews from damper

    Wren 150mm Tuning/Setup Guide-20160205_223958_resized_1.jpg

    Top cap, side view, showing some damping circuit

    Wren 150mm Tuning/Setup Guide-20160205_224015_resized_1.jpg

    Damper tube, top view, note small oil hole, there are two, these allow oil flow in and out of rubber bladder

    Wren 150mm Tuning/Setup Guide-20160205_224044_resized_1.jpg

    Damper adjustment rod and plunger. My damper failure was due to the plunger having become unscrewed from the rod. A little thread lock would solve that problem.
    Wren 150mm Tuning/Setup Guide-20160205_224159_resized_1.jpg

    Disassembled layout, rod inserts from bottom of damper, plunger screws onto rod from above, plunger pulled down, oil added, pull vacuum to remove air (?), reinstall cap.
    Wren 150mm Tuning/Setup Guide-20160205_224318_resized_1.jpg

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    Quote Originally Posted by Nurse Ben View Post
    One of the things that fork mfgs need to consider is that many end users do want the option of adjusting fork performance.

    ... I'm not a fork oil expert, but in my research,....
    Actually, the only thing stopping me from getting a Wren over the Bluto is the need for me to adjust the fork for it to perform properly. I have been reading this thread as it has unfolded all this time and one absolute matter I can conclude is that the Wren has to be adjusted. I am pretty comfortable with wrenching bikes as I have done the past 42 odd years.

    I assemble my own bikes (mostly road) and even build my own wheels from scratch. I can disassemble my Cannondale Scalpel and rebuild it back in a day. However, I am looking for a fat bike fork that needs no work for it to - work. Something like my Lefty XLR fork which has performed 100% from the day I bought it last year. Any small or big problems (which I have none) can and will be worked on by the Cannondale dealership as part of the warranty.

    Kudos to you for doing these multitude of adjustments on your Wren to make it work. If you are not an expert on forks (oil, damper, etc. whatever), then who is? I do not see anyone her that comes close to your expertise on this matter.

    But if I were Russ and the folks at Wren, I would be worried that MTBRs -- who read about your experience and the extent of what you have done to make your fork work - will effectively veer away from it until the kinks have been worked out.

    I almost bought one until I started reading this thread. I was already emailing them with some questions. I have since put it off.

    Thank you for your contribution but alas to Wren it has just made me postpone my purchase. I may not even buy it at all.

    Good job on your fork. And good luck.

  82. #82
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    I think my situation was just bad luck, a glitch in the assembly, I wouldn't let my experience color the entire Wren fork user experience.

    Most users seemed to have no difficulties; those folks don't post, so what you see here are just the ones who got lucky and did the work to solve the problems.

    In time I'm sure the Wren will prove to be a reliable "plug and play" suspension fork, not unlike the Bluto; the Bluto also had some early release issues with failed air side seals and bad dampers.

    The Wren is the only long travel, 150mm hub spaced suspension fork, and it is the burliest fat bike suspension made. If these are things you need, then the Wren is the fork for you.

    Quote Originally Posted by paxfobiscum View Post
    Actually, the only thing stopping me from getting a Wren over the Bluto is the need for me to adjust the fork for it to perform properly. I have been reading this thread as it has unfolded all this time and one absolute matter I can conclude is that the Wren has to be adjusted. I am pretty comfortable with wrenching bikes as I have done the past 42 odd years.

    I assemble my own bikes (mostly road) and even build my own wheels from scratch. I can disassemble my Cannondale Scalpel and rebuild it back in a day. However, I am looking for a fat bike fork that needs no work for it to - work. Something like my Lefty XLR fork which has performed 100% from the day I bought it last year. Any small or big problems (which I have none) can and will be worked on by the Cannondale dealership as part of the warranty.

    Kudos to you for doing these multitude of adjustments on your Wren to make it work. If you are not an expert on forks (oil, damper, etc. whatever), then who is? I do not see anyone her that comes close to your expertise on this matter.

    But if I were Russ and the folks at Wren, I would be worried that MTBRs -- who read about your experience and the extent of what you have done to make your fork work - will effectively veer away from it until the kinks have been worked out.

    I almost bought one until I started reading this thread. I was already emailing them with some questions. I have since put it off.

    Thank you for your contribution but alas to Wren it has just made me postpone my purchase. I may not even buy it at all.

    Good job on your fork. And good luck.

  83. #83
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    NurseBen could you explain to me what part is moving when using the compression knob? Since I am curious why the compression is only changing in the last few millimeters. Is that due a piston not moving like it should over the Wholes or something....???

  84. #84
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    That's a good question!

    I hadn't really thought about it, but I assume that when the damper is completely inserted into the stanchion, the piston inserts into the base of the damper "cap" and this limits rotation, so then the piston itself has a limited number of rotations before it binds.

    I would assume that as the piston rises, the flow of oil through the pathways is restricted.

    My new damper is fully functional, I can feel a difference going from 1 turn to 2 turns, and at 4 turns the damper is so effective that it literally stops the fork from returning to full extension.

    I'll play with the old damper tonight so I can better understand how it works.

    Russ wants the damper back, so no oil changes for the old one

    Quote Originally Posted by Rumblefish2010 View Post
    NurseBen could you explain to me what part is moving when using the compression knob? Since I am curious why the compression is only changing in the last few millimeters. Is that due a piston not moving like it should over the Wholes or something....???

  85. #85
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    That damper seems incredibly crude, like the old Marzocchi TST found in the All-Mountain forks. There was no shimmed high speed compression, just a heavy washer controlled by a blow-off spring and no high-speed rebound circuit.

    A Pike Charger or Fox FIT looks similar from outside, but inside it has needles controlling low speed bleed and pistons with check valves and pyramid shim arrangements.

    I'm interested because I just took two of my charger dampers apart yesterday, switching pistons on them, but that fork in the picture seems like it takes many steps back in terms of damping? Unless there are compression and rebound pistons in there we are not seeing?
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  86. #86
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    Does anyone else have an issue with the axel on the Wren loosening up on a ride? Twice now the wheel is loose and the axel is loose. When I tighten it, it is hard to cam over, then I find it loose enough to swing back and forth. Should I just put a drop of threat lock tire on it?

  87. #87
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    Nope, not a problem.

    But my stem wouldn't go tight enough last night when I was riding in the cold and wet, so I kept steering sideways...cheap ass RF stems

    Quote Originally Posted by JCHKeys View Post
    Does anyone else have an issue with the axel on the Wren loosening up on a ride? Twice now the wheel is loose and the axel is loose. When I tighten it, it is hard to cam over, then I find it loose enough to swing back and forth. Should I just put a drop of threat lock tire on it?

  88. #88
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    A little video from yesterday. The final scene with the jump is 21 inches high, that was the first run on it. Later runs I doubled the speed and started sending it.

    https://youtu.be/9ONy8mdlgNk

  89. #89
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    Quote Originally Posted by JCHKeys View Post
    Does anyone else have an issue with the axel on the Wren loosening up on a ride? Twice now the wheel is loose and the axel is loose. When I tighten it, it is hard to cam over, then I find it loose enough to swing back and forth. Should I just put a drop of threat lock tire on it?
    I have experienced that a few times. I have noticed that it happenes when you put on the Wheel in the work stand. I have been not having the problem when tightening the axle when the bike is on the floor. And I try to do some cycling of the fork and recheck if it is tight enough.

  90. #90
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    Quote Originally Posted by paxfobiscum View Post
    Actually, the only thing stopping me from getting a Wren over the Bluto is the need for me to adjust the fork for it to perform properly. I have been reading this thread as it has unfolded all this time and one absolute matter I can conclude is that the Wren has to be adjusted. I am pretty comfortable with wrenching bikes as I have done the past 42 odd years.

    I assemble my own bikes (mostly road) and even build my own wheels from scratch. I can disassemble my Cannondale Scalpel and rebuild it back in a day. However, I am looking for a fat bike fork that needs no work for it to - work. Something like my Lefty XLR fork which has performed 100% from the day I bought it last year. Any small or big problems (which I have none) can and will be worked on by the Cannondale dealership as part of the warranty.

    Kudos to you for doing these multitude of adjustments on your Wren to make it work. If you are not an expert on forks (oil, damper, etc. whatever), then who is? I do not see anyone her that comes close to your expertise on this matter.

    But if I were Russ and the folks at Wren, I would be worried that MTBRs -- who read about your experience and the extent of what you have done to make your fork work - will effectively veer away from it until the kinks have been worked out.

    I almost bought one until I started reading this thread. I was already emailing them with some questions. I have since put it off.

    Thank you for your contribution but alas to Wren it has just made me postpone my purchase. I may not even buy it at all.

    Good job on your fork. And good luck.
    I think Wren will sort out these issues now, and when that is good, I cannot imagine that it should be any problems to be solved. It is a really simple fork to maintance, and you do not have to fear anything.

  91. #91
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    I hope so. My foot is healing from surgery so I am not 100% on my riding technique and have not gone to aggressive trails. At this juncture, I am okay with my stiff fork. However, I will eventually get a suspension fork for my Fatty and I am really trying to find any reason to get the Wren over the Bluto. It has not been easy...

  92. #92
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    I think the question should be: Is there any reason to get the Bluto over the Wren?

    The Bluto is one pound lighter than the Wren.

    The Bluto is less expensive than the Wren.

    For me, I needed a fork with more travel and less flex. I could have gotten that with a dual crown fork, but that would have required hub changes and clearance would have been tight on a 4" tire; no 5" tires allowed.

    I could also have gotten a Fox plus, more or less the same weight as a Bluto, fairly higher performance with a good reputation, but clearance would be tight and again it would require hub changes.

    If I needed a lightweight fork with limited travel (80mm), I'd get a Lauf.

    Having ridden three Blutos on three different bike (FS, Rigid, Tandem), I don't have a ton of love for this fork. On my tandem it was worse than rigid, on the other two bikes it was better than rigid. The Bluto is essentially a Reba, the design is old, the function is limited, and it's a noodle.

    The Wren is 150mm hub compatible, it has a variety of travel options, it is easily serviceable, and the developers are working to improve it.

    A better damper will emerge, either aftermarket or from Wren. I think the cold weather damper issues will be resolved with an oil change, otherwise there will be some damper reworking. Because of the fork's design, changing components is easy, and upgrading is going to be equally easy.

    If there were a fat Pike, I'd ride it, but there isn't one, and quite honestly I don't expect one unless a big player starts building FS fatties.

    Good luck with the foot.

    Get a Wren.

    Quote Originally Posted by paxfobiscum View Post
    I hope so. My foot is healing from surgery so I am not 100% on my riding technique and have not gone to aggressive trails. At this juncture, I am okay with my stiff fork. However, I will eventually get a suspension fork for my Fatty and I am really trying to find any reason to get the Wren over the Bluto. It has not been easy...

  93. #93
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    How much pressure are you running? How much do you weigh?

    I run 60/60, this makes for a very supple feel, no bottoming. I weigh 200#.

    Quote Originally Posted by JCHKeys View Post
    A little video from yesterday. The final scene with the jump is 21 inches high, that was the first run on it. Later runs I doubled the speed and started sending it.

    https://youtu.be/9ONy8mdlgNk

  94. #94
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    I am about 230 geared up, I am running 70/50 if I am correct, I filled in warm and it was 24 degrees in those shots... I am still playing with pressure. Rebound is at about 2/3 towards fast, mid was just a bit too slow.

  95. #95
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    I run 60 in top Chamber and I fill the bottom Chamber until I feel the bottom out resistance is good enough. I think 60 in top Chamber gives me about 30% sag. I am 250 geared up, and I use all travel. I found the fork to be to firm With more than 60 in top Chamber. Using as little rebound damping as possible, and if I am doing a lot of climbing standing, I just put om more compression.

    It is really difficult to see JCHKeys, but it seems by the video that you have a really firm fork. But if you ride hard and do much jumps, thats the way to go. But I think you will work hard to get bottoming out with less air in top Chamber, if you adjust the bottom Chamber to give enough bottom out resistance. Actually I see the bottom Chamber as an "adjustable bottom out resistance token".


    Quote Originally Posted by JCHKeys View Post
    I am about 230 geared up, I am running 70/50 if I am correct, I filled in warm and it was 24 degrees in those shots... I am still playing with pressure. Rebound is at about 2/3 towards fast, mid was just a bit too slow.

  96. #96
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    I'm not sure there is an ideal way to get a big pressure difference in the upper and lower chambers due to the relatively low air volvume in the lowers, so I found it was easiest to just run the same pressure top and bottom.

    In the video it did appear that the fork was stiff, even off the jump it barely moved. This might be fine at the park, but for trail riding I want some cushion.

    So JCH, what are you running for pressure on your CCInline?

    When I ran a higher pressure (75psi) to adjust for sag; though it appeared that I would be in a "good place" in terms or bottom out and utilizing all of my travel, I found that I didn't get the full extent of travel in trail use, so I backed off to 60psi and now it feels supple, sag is good, and I use all of my travel without bottoming.

    Russ said that the Foes guys were running lower pressures as well.

  97. #97
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    I watched the Annabelle video, very cute, her mommy must have really enjoyed watching that

    Ah, to be a little kid, pulled along by your dad, dragging her hands in the snow like it was water, so fun!

    Quote Originally Posted by JCHKeys View Post
    A little video from yesterday. The final scene with the jump is 21 inches high, that was the first run on it. Later runs I doubled the speed and started sending it.

    https://youtu.be/9ONy8mdlgNk

  98. #98
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    Actually it cannot be any difference in the upper and lower Chambers air pressure, since it will equalize by the plunger moving up and down. The lower Chamber is not a defined volume, the two Chambers are divided by a moving plunger. So by increasing air in the upper Chamber will give the exactly same pressure in the bottom Chamber. You will read 75psi top and bottom if you use 75psi for example in the top Chamber. Therefore it is the way to fill in like 30-40 psi in the lower, setting the correct sag With filling the top Chamber, and then addin air to the lower Chamber to get the bottom out resistance you want. The confusing part is when you add pressure in the bottom Chamber it will increase in the top Chamber, since you are expanding the lower and decreasing the upper Chamber.

    Quote Originally Posted by Nurse Ben View Post
    I'm not sure there is an ideal way to get a big pressure difference in the upper and lower chambers due to the relatively low air volvume in the lowers, so I found it was easiest to just run the same pressure top and bottom.

    In the video it did appear that the fork was stiff, even off the jump it barely moved. This might be fine at the park, but for trail riding I want some cushion.

    So JCH, what are you running for pressure on your CCInline?

    When I ran a higher pressure (75psi) to adjust for sag; though it appeared that I would be in a "good place" in terms or bottom out and utilizing all of my travel, I found that I didn't get the full extent of travel in trail use, so I backed off to 60psi and now it feels supple, sag is good, and I use all of my travel without bottoming.

    Russ said that the Foes guys were running lower pressures as well.

  99. #99
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    Yes, I've noticed that, which is why I just keep them the same.

    At one point I tried 50 upper and 75 lower, just to see how it would ride, but in the end I wanted a plusher feel, so 60/60 works for me.

    Quote Originally Posted by Rumblefish2010 View Post
    Actually it cannot be any difference in the upper and lower Chambers air pressure, since it will equalize by the plunger moving up and down. The lower Chamber is not a defined volume, the two Chambers are divided by a moving plunger. So by increasing air in the upper Chamber will give the exactly same pressure in the bottom Chamber. You will read 75psi top and bottom if you use 75psi for example in the top Chamber. Therefore it is the way to fill in like 30-40 psi in the lower, setting the correct sag With filling the top Chamber, and then addin air to the lower Chamber to get the bottom out resistance you want. The confusing part is when you add pressure in the bottom Chamber it will increase in the top Chamber, since you are expanding the lower and decreasing the upper Chamber.

  100. #100
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    I do not get different Readings from bottom and top Chamber. Connecting two shock pumps, you will get the same Reading when going to a higher psi. If you go lets say to 60psi in top Chamber it will change in the lower to 60psi simultaneously and vise versa if you fill more in bottom Chamber it will increase Automatic in top chamber....It cannot be changed pressure in one chamber without getting changed pressure in the other, since the pressure is balancing between the the two....

    Quote Originally Posted by Nurse Ben View Post
    Yes, I've noticed that, which is why I just keep them the same.

    At one point I tried 50 upper and 75 lower, just to see how it would ride, but in the end I wanted a plusher feel, so 60/60 works for me.

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