how to safely make a head angle more SLACK?- Mtbr.com
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  1. #1
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    how to safely make a head angle more SLACK?

    OK, so if I wanted to make a HA more slack what choices are there?

    1. longer front fork Axle to Crown or get a triple crown fork
    2. Real World Headset ďexternalizerĒ http://www.enduroforkseals.com/id183.html
    3. If you have a CK headset, they make a 7mm race
    4. Head tube extender (I donít think this would be safe on a mountain bike do you?) http://cgi.ebay.com/EIGHTHINCH-HEADT...item2ea69fc44d

    Anything else?

    Most of the above wont work for me, I donít have or want a triple crown fork, I donít want a longer travel front fork, I donít have the proper head tube for option 2, I donít have a CK headset, and I am not sure I want to pay over $100 for one and add $27 for the spacer just to get 7mm, and I am not sure how safe option 4 is.

    Any other options? I would like 10-15mm.

    Thanks

  2. #2
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    Quote Originally Posted by rodH
    OK, so if I wanted to make a HA more slack what choices are there?

    1. longer front fork Axle to Crown or get a triple crown fork
    2. Real World Headset ďexternalizerĒ http://www.enduroforkseals.com/id183.html
    3. If you have a CK headset, they make a 7mm race
    4. Head tube extender (I donít think this would be safe on a mountain bike do you?) http://cgi.ebay.com/EIGHTHINCH-HEADT...item2ea69fc44d

    Anything else?

    Most of the above wont work for me, I donít have or want a triple crown fork, I donít want a longer travel front fork, I donít have the proper head tube for option 2, I donít have a CK headset, and I am not sure I want to pay over $100 for one and add $27 for the spacer just to get 7mm, and I am not sure how safe option 4 is.

    Any other options? I would like 10-15mm.

    Thanks
    Get another bike? Seems like the most expensive option though.

    Really though, run a smaller tire in the back (2.0, 2.2, whatever you are comfy with) and a BIG tire up front...big volume, like the 2.4 Maxxis, 2.4 Schwalbe, 2.5 Kenda.

  3. #3
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    29" in front, 26" in back.
    Get a new bike.
    I recommend you quit obsessing about something that will hardly make a noticable difference. If you want 10-15 mm increase (in front height?), that probably wouldn't even change the head angle by 1 degree.
    An adjustable fork like a Talas will change your fork length by much more than that, and you would still have the option of dropping it down if (for whatever reason), you want a short travel fork.

  4. #4
    Te mortuo heres tibi sim?
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    WHat frame/what fork?

    Cane Creek makes this:

    http://www.universalcycles.com/shopp...s.php?id=13922

    And I have used it in conjunction with the King taller lower race, briefly. That would get you what you want. Not sure how secure things wold be, depending on how and where you ride. I ran mine shortly, then went for the other fork/frame option.
    Florence Nightingale's Stormtrooper

  5. #5
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    Quote Originally Posted by smilinsteve
    29" in front, 26" in back.
    Get a new bike.
    I recommend you quit obsessing about something that will hardly make a noticable difference. If you want 10-15 mm increase (in front height?), that probably wouldn't even change the head angle by 1 degree.
    An adjustable fork like a Talas will change your fork length by much more than that, and you would still have the option of dropping it down if (for whatever reason), you want a short travel fork.
    Rule of thumb is that 10mm change in A2C = .5* change in HA.

  6. #6
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    Quote Originally Posted by scrublover
    WHat frame/what fork?

    Cane Creek makes this:

    http://www.universalcycles.com/shopp...s.php?id=13922

    And I have used it in conjunction with the King taller lower race, briefly. That would get you what you want. Not sure how secure things wold be, depending on how and where you ride. I ran mine shortly, then went for the other fork/frame option.
    How would you use that WITH the CK race?

  7. #7
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    Quote Originally Posted by CharacterZero
    Get another bike? Seems like the most expensive option though.

    Really though, run a smaller tire in the back (2.0, 2.2, whatever you are comfy with) and a BIG tire up front...big volume, like the 2.4 Maxxis, 2.4 Schwalbe, 2.5 Kenda.

    I should have been more specific. I run a Nevagal 2.35 F and 2.1 rear.

  8. #8
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    Quote Originally Posted by rodH
    I should have been more specific. I run a Nevagal 2.35 F and 2.1 rear.
    Yeah, go to a 2.7 front, that'll fixya.

  9. #9
    Te mortuo heres tibi sim?
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    Quote Originally Posted by rodH
    How would you use that WITH the CK race?
    Is that a trick question?

    You would just use the King race rather than the CC race. I ran it a bit, and didn't find any discernable problem with the King race or the CC lower bearing after doing so. I've also used the King lower race with other non-King headsets without any issue. Obviously the shape of the race and bearing interface is key - some won't work, some will work fine, some not so much.

    I have no idea if it is something that would stress anything on the frame or fork more by doing so or not though, so obviously do at your own risk. If something happened, I'm sure all warranties would be voided, should you care about such.
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  10. #10
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    wow - triple crown forks??
    geez, who makes those and why?
    or does that have something to do w/ horse racing
    Honestly... ahh I give up

  11. #11
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    Quote Originally Posted by rodH
    OK, so if I wanted to make a HA more slack what choices are there?
    All those methods raise BB, slacken seat angle, so you move back and climbing suffers.

    The best method is to buy a new frame.

  12. #12
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    Quote Originally Posted by Curmy
    All those methods raise BB, slacken seat angle, so you move back and climbing suffers.

    The best method is to buy a new frame.

    To me that is a little extreme. Moving a seat angle back .5 degree is easily fixed by moving the seat foward on the rails (you know you can do that right?). Raising the BB 4-5mm isn't a big deal to me either. BIkes with 5-6" of travel need to have the BB raised.

  13. #13
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    Quote Originally Posted by scrublover
    Is that a trick question?

    You would just use the King race rather than the CC race. I ran it a bit, and didn't find any discernable problem with the King race or the CC lower bearing after doing so. I've also used the King lower race with other non-King headsets without any issue. Obviously the shape of the race and bearing interface is key - some won't work, some will work fine, some not so much.

    I have no idea if it is something that would stress anything on the frame or fork more by doing so or not though, so obviously do at your own risk. If something happened, I'm sure all warranties would be voided, should you care about such.
    Great, thanks for the advice!! Sounds like the CK race and the CC race/bearing surfaces must be the same or similar for them to work together, this is the valuble type of information that only comes from experience and the help of members on boards like these.

  14. #14
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    Quote Originally Posted by rodH
    To me that is a little extreme. Moving a seat angle back .5 degree is easily fixed by moving the seat foward on the rails (you know you can do that right?). Raising the BB 4-5mm isn't a big deal to me either. BIkes with 5-6" of travel need to have the BB raised.
    If raising BB 5mm is not a big deal - why raising front by 5mm with some tall race is worth bothering? If you move saddle forward, you would need to lengthen stem by the same amount to preserve fit, which also affects handling.

  15. #15
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    Quote Originally Posted by rodH
    BIkes with 5-6" of travel need to have the BB raised.
    Depends.

  16. #16
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    OP - what stem are you running?

    Try reducing your stem length - that will have a much larger effect on confidence in the steeps.

    We can only assume that is what you are after, since you haven't actually told us why you want what you are asking about.

  17. #17
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    Quote Originally Posted by CharacterZero
    OP - what stem are you running?

    Try reducing your stem length - that will have a much larger effect on confidence in the steeps.

    We can only assume that is what you are after, since you haven't actually told us why you want what you are asking about.
    I am running a 80mm stem, I tried a 60 and it felt a bit too short. I also plan on going from a 25" wide bar to a 27" (and if that is too long, cut it down from there). I agree, those things will help, but HA also seems to be a key component as well. Maybe after getting the new bars I will find that I am plenty stable for the DH sections.

  18. #18
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    Quote Originally Posted by rodH
    I am running a 80mm stem, I tried a 60 and it felt a bit too short. I also plan on going from a 25" wide bar to a 27" (and if that is too long, cut it down from there). I agree, those things will help, but HA also seems to be a key component as well. Maybe after getting the new bars I will find that I am plenty stable for the DH sections.
    You are saying that a 60mm stem felt too short to be secure on downhill sections?

  19. #19
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    Quote Originally Posted by rodH
    I am running a 80mm stem, I tried a 60 and it felt a bit too short. I also plan on going from a 25" wide bar to a 27" (and if that is too long, cut it down from there). I agree, those things will help, but HA also seems to be a key component as well. Maybe after getting the new bars I will find that I am plenty stable for the DH sections.
    80mm sounds kind of long..

    Do you run an adjustable seatpost with a handlebar remote? That's the very best upgrade you can make to feel stable on downhill and still climb well.

  20. #20
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    Quote Originally Posted by CharacterZero
    You are saying that a 60mm stem felt too short to be secure on downhill sections?
    The 60 is fine Down, climbing I didn't like it and I feel a little cramped.

    I don't use an adjustable seat post, that part doesn't really bother me, I guess I am old school and have learned to deal with the seat in the way, just have to work around it.

  21. #21
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    Quote Originally Posted by rodH
    I don't use an adjustable seat post, that part doesn't really bother me, I guess I am old school and have learned to deal with the seat in the way, just have to work around it.
    Try an adjustable seatpost. It is a mind altering experience. All the measures you are considering are inconsequential in comparison.

    Just ask anybody who uses one. I have switched fairly recently and I can not understand how I could live without one. I run AMP post - recommended.

  22. #22
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    Quote Originally Posted by rodH
    The 60 is fine Down, climbing I didn't like it and I feel a little cramped.

    I don't use an adjustable seat post, that part doesn't really bother me, I guess I am old school and have learned to deal with the seat in the way, just have to work around it.
    Yep, it is all about compromises. You make the call - I found that I loved going to a 40mm from a 70mm, but suffered too much on the ups. I made all the climbs by altering technique (search for "f&ck the football), but it was too much. I think I'd be happy to try a 55mm, but they are rare, and I am happy where I am.

  23. #23
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    Quote Originally Posted by highdelll
    wow - triple crown forks??
    geez, who makes those and why?
    or does that have something to do w/ horse racing
    Hahaha. It must be that third crown that adjusts the head angle.

  24. #24
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    It would help greatly if the OP posted up what frame/fork/headset he is using at the moment...
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  25. #25
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    Find the highest stack headset you can?
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  26. #26
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    Quote Originally Posted by scrublover
    It would help greatly if the OP posted up what frame/fork/headset he is using at the moment...
    Not sure how helpful it is going to be since the frame is so old and the geo is hard to find.
    It is a 1997 Specialized FSR DH MAX Backbone frame (it was considered a "DH" with just over 5.25" of rear travel back then). I have added a BETD adjustable rear link and bearings at all pivots. The HA right now as I can measure it is right at about 69 degrees. This is with a 1999 Z1 130mm travel fork at 500 axle to crown measurement. I am building it up with a 140mm travel Fox Vanilla with a 510mm axle to crown. The headset is an old FSA that looks like a King copy on the outside, but uses normal ball bearings (not sealed). I love the frame and have been really stoked since I added the BETD link and bearing kit. The link actually lets me go to 4.5/5.6 or 6.7" travel. I could slacken the HA with droping the link to 4.5" travel mode, but I want more travel than that. I like it at 5.6"

    I am thinking the taller Cane Creek and maybe the CK race will do the trick

  27. #27
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    That head tube extender looks like it would work, but you need to have enough steerer tube to handle it. there would be some additional headtube stress, but I think a slacker angle has inherently more headtube stress no matter how you achieve it.

  28. #28
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    Gotcha. With a frame that old, I'd be leery of adding too many variables to the headtube area. Run the Fox with its 10mm taller height, and the CC +5 and call it good. Taht right there gets you the numbers you say you want, without adding more complexity/things to go wrong/more height on the front end of a frame not really meant for it.

    No matter how burly it was then, it's now 10+ years of aged aluminum frame.

    Do the taller fork/headset and start saving for a new frame eventually.


    Quote Originally Posted by rodH
    Not sure how helpful it is going to be since the frame is so old and the geo is hard to find.
    It is a 1997 Specialized FSR DH MAX Backbone frame (it was considered a "DH" with just over 5.25" of rear travel back then). I have added a BETD adjustable rear link and bearings at all pivots. The HA right now as I can measure it is right at about 69 degrees. This is with a 1999 Z1 130mm travel fork at 500 axle to crown measurement. I am building it up with a 140mm travel Fox Vanilla with a 510mm axle to crown. The headset is an old FSA that looks like a King copy on the outside, but uses normal ball bearings (not sealed). I love the frame and have been really stoked since I added the BETD link and bearing kit. The link actually lets me go to 4.5/5.6 or 6.7" travel. I could slacken the HA with droping the link to 4.5" travel mode, but I want more travel than that. I like it at 5.6"

    I am thinking the taller Cane Creek and maybe the CK race will do the trick
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  29. #29
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    Quote Originally Posted by scrublover
    Gotcha. With a frame that old, I'd be leery of adding too many variables to the headtube area. Run the Fox with its 10mm taller height, and the CC +5 and call it good. Taht right there gets you the numbers you say you want, without adding more complexity/things to go wrong/more height on the front end of a frame not really meant for it.

    No matter how burly it was then, it's now 10+ years of aged aluminum frame.

    Do the taller fork/headset and start saving for a new frame eventually.
    I agree, that is probably the best bet. The frame was actually designed as a DH frame, built extruded and came with a Boxxer DOUBLE clamp fork and 5.25" of rear travel, so it was built pretty stout, plus I don't think there is a "shelf life" with aluminum outside of riding and abuse. I don't want to get to crazy though, and thats why I figure a 5.5" fork should be about the limit.

  30. #30
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    If you have a 1.5" headtube with a 1 1/8" steerer fork a company makes offset reducer cups which they claim give you 2deg, depending on your head tube length.

  31. #31
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    Years ago I owned a Klein mantra and that bike had a steep head angle. It would flip me over the handlebar on real steep slopes. I changed out the shock and installed one 1/2" shorter and it made all the difference in the world. The bike sat a bit lower and longer. I was very happy with the bike after that.

  32. #32
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    650b front wheel raises the axle 1/2in/12.7mm. With the same volume tire the bigger wheel adds slower steering trail, slacks the frame 1/2 degree, easier rollin and increased turning and braking grip. Most of the advantages of a 2.7 tire on a 26 inch rim but less than 100 grams increase in weight. Sharp hits feel like the bike has another 1 inch of travel, without any added brake dive. Most 26 inch wheel forks clear 650b tires safely.

    650b wheels are mostly custom made still, so about $250 for a front + tire.

  33. #33
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    Quote Originally Posted by rodH
    I agree, that is probably the best bet. The frame was actually designed as a DH frame, built extruded and came with a Boxxer DOUBLE clamp fork and 5.25" of rear travel, so it was built pretty stout, plus I don't think there is a "shelf life" with aluminum outside of riding and abuse. I don't want to get to crazy though, and thats why I figure a 5.5" fork should be about the limit.
    The DH and DC forks of 1999 are not those of today. I'd be very leery of putting anything much taller than your planned 140mm on the front end of a frame of that vintage.

    Try the Fox fork, the CC headset, and a compromise stem of 70mm. That may give the sweet spot for that bike.
    Florence Nightingale's Stormtrooper

  34. #34
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    On my XC hardatil Zaskar 29 Carbon 2019 it is hard to slacken the head angle because the headset is IS (integrated, without cups, you cannot mount angleset on those).

    So I installed production privee 18mm headset extension (don't forget to remove the crown race before installing, and be sure your fork steerer is long enough).
    https://production-privee.com/en/pro...set-extension/

    Works fine, the bike is calmer on downhill, not a huge change but really worth it.


    I cannot see any potential danger for the frame, or the fork. It is just a crown race which is 18mm longer than the original.

  35. #35
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    Quote Originally Posted by nicolasswid View Post
    On my XC hardatil Zaskar 29 Carbon 2019 it is hard to slacken the head angle because the headset is IS (integrated, without cups, you cannot mount angleset on those).

    So I installed production privee 18mm headset extension (don't forget to remove the crown race before installing, and be sure your fork steerer is long enough).
    https://production-privee.com/en/pro...set-extension/

    Works fine, the bike is calmer on downhill, not a huge change but really worth it.


    I cannot see any potential danger for the frame, or the fork. It is just a crown race which is 18mm longer than the original.
    Wow. Bringing back a 10 year old zombie thread.

  36. #36
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    Quote Originally Posted by nicolasswid View Post
    I cannot see any potential danger for the frame, or the fork. It is just a crown race which is 18mm longer than the original.
    You've added 18mm more to the axle to crown. You're probably fine but would want to double check what the frame manufacturer says is max for axle to crown. If you're within 20mm you most likely will be fine, but if you are way out of spec you may want to give it a second thought.

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