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  1. #1
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    Lefty Max Rebuild illustrated

    Well, I've done this twice now - with much the same experience - so I thought I would share. I don't know how to get the pics inline with the text, so I apologize in advance for making you scroll bakNforth.

    The basics: I own 2 Lefty Max's; a 130 TPC(converted to 1 1/8) (Pic1/2 - oops, no rebound damper asm shown) and a 140 carbon SPV(converted to 1 1/8 and 29er) (Pic3/4). Both of them have blown the rebound shaft seal at the top of the lower and started leaking oil out the boot. Both had a simple ORing, but now have a Quad seal (Pic5).

    To replace the rebound shaft seal, you follow the owners manual instructions to 1) take out the spring and 2) change the oil. Taking out the spring exposes the rebound shaft & seal, and changing the oil removes the compression damper, gets the oil out of the way, and lets you remove the rebound damper assembly to get it out of the way. All you need now is a 19mm socket, an 8" extension and a ratchet to remove the rebound shaft seal cap. Its the nut/washer looking bit between the bearing strips and the lower clamp in Pic 3. You will need a dental pick or something to hook the old seal out of the inside groove. Make sure the holder is clean, wet the new seal with oil and slip it into the groove - making sure its neatly in place with no rumples.
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    This isn't a "you're doing it wrong" topic.

    WSS/OSS: Open Source Sealant

  2. #2
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    Part II

    So you might ask: why did you pull your telescopes apart when you don't need to do that to fix the rebound shaft seal?


    Well..... the seal leaks oil all thru the bearings and washes out the grease - so you need to clean it out as much as possible. And as you are doing this, you may notice that you should reset your bearings because one or more is not aligned with the others - as you cycle the telescope backNforth, you will notice that the bearings will leave a little lube line where they stop, and its easy to tell if they are aligned.

    Now, resetting bearing migration is easy - and covered in other threads as well as the owners manual. BUT! At this point, you have removed the rebound shaft seal holder - which apparently acts as the upper retainer of the bearing strips. With both Leftys my attempts at resetting while apart have resulted in pulling the telescope apart. And I note that in both cases I was checking alignment after each whack! And had not got it before sproing!

    OTOH, since I now had the beast apart, cleanup and regrease was easy. And now I know how to reassemble the telescope to boot

    To properly disassemble the telescope, you unscrew the large nut at the bottom of the upper (alloy) or pop out the wire internal snapring (carbon), remove the polyethylene bushing to expose the upper race retainer, unclip the upper races (T shaped) from the retainer by pushing the race to the inside while pulling on the retainer (hard to get it started, but it gets easier) and remove the retainer ring (these 3 parts are in the upper left of Pic3) Now the telescope can just slide apart - but you should be ready to catch parts and make sure you know where they were so you can get them back there - not critical but best practice.

    Now you clean everything, lightly regrease, and put all the parts onto the lower as shown in the pic. Except that you can't see all the parts (retainer/bushing/nut or snapring) that have to be on the lower before you start with races/bearing. And on the Carbon, you better pull the boot and air cleaner onto the upper before you put things together too!

    Lower races in place (wanting to bow out in the middle) and fully seated at the bottom, bearing strips halfway on (mid strip at top of lower) and upper races with the "T" two or three bearings down from the top and arcing out away from the assembly (which will put the middle bowing out from the inside of the upper). You may notice the "special tool" - which is actually two plastic caps fattened up with electrical tape. This makes life much easier for you, but don't get it any larger than the flat-to-flat dimension of the lower - it can pinch the bearing strip if you do. Once you have it together the tool will fall out the end easily.

    Then hold the lower/etc with one hand and pick up the upper in the other. "Clock" them correctly ( look at clamps vs axle) and slowly lower the parts together, lightly twisting them backNforth to make sure things are lining up. Keep an eye on the position of the upper races and the bearing strips to make sure they stay aligned. If something slips, back off and realign.

    When you're done, you may notice that now the upper races stick out too far. This is why you put the upper races together not in the middle of the bearing strips, and it makes it easier to get the T's into the retainer clip. You will have to "reset" the races/bearings a bit to get the clip seated, so if you think its easier to clip the races in down in their hole put things together centered.

    With the Alloy, you can use the big nut to push things into alignment as long as you are close enough to get threads started. Easy-squeezy. With the Carbon, you have to move the snapring onto the axle collar, make a sleeve (basically just like the bushing except slit so you can take it off later) to push everything down past the snapring groove and then just like bearing reset - except in reverse: whack it together instead of apart.

    Now reassemble the rebound damper shaft& seal, then hod it upside down and filler up (not to the top!) with oil, insert the compression damper -making sure that it is pushing the least little bit of oil out as it seats to make sure there is no air (holding a rag around the end will catch this).

    Zip the boot down, reinstall the spring, and put'er back on the bike. Don't forget to reset the damper dials
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    This isn't a "you're doing it wrong" topic.

    WSS/OSS: Open Source Sealant

  3. #3
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    I'm hoping I won't need to do this for a while, but is that quad seal a Cannondale part they are now using, or aftermarket? If Cannondale, when did they go from the O-ring to the Quad Ring?

  4. #4
    discombobulated SuperModerator
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    I believe the quad seal is Cdale, and they went to it in the last year or ...two? Someone should know for sure..
    CDT
    NICE WRITE UP!

  5. #5
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    Comments

    The quad seal is standard from CDale - but you have to buy the seal kit, which has everything in it., including the closed cell foam sheet that allows for volume change w/o air inside the damper on the TPC and FFD. One kit fits all 140, I think there is another for all 130.


    I hope you all get enjoy the writeup, I can tell I shoulda taken more pics - but with two greasy hands busy the camera stays put.
    This isn't a "you're doing it wrong" topic.

    WSS/OSS: Open Source Sealant

  6. #6
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    so whats the point of the quad seal? and which leftys have that?

  7. #7
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    Quad good

    The original Oring makes a simple line of contact with the housing on one side and the rebound shaft on the other. When you take a big hit and push the rebound shaft way down into the oil - you effectively pressurize the oil chamber (the foam sheet acts as a spring). On both my Leftys it took about a year to toast the Oring and start blowing oil thru the bearings onto the front brake/etc.

    The quad seal is nearly square and fills the groove almost fully - as opposed to the round ring in the square groove. The quad seal has at least twice as much area to hold pressure as the Oring, and should last at least twice as long.

    I thought the quadseal came in with the 140 - but apparently not since my 140 had an Oring. Definitely at least a year now.
    This isn't a "you're doing it wrong" topic.

    WSS/OSS: Open Source Sealant

  8. #8
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    Owners Manual?

    Great information! Do you have an electronic source for the owners manual? I did not receive detailed instructions with my fork.I have to replace my seal... If I understand you right, I remove the upper spring (this I've done before) and remove the lower bladder assembly (this too) and dump out the oil, remove the damper assembly (pull out?) With a 19mm socket and 8" extension I unscrew the nut from the bottom assembly and pull the unit apart. The o' ring is in a grove is located in the upper part of the assembly(??)... Remove it and replace with upgraded quad seal.

    It appears your picture (carbon lefty) is showing the approximate actual location of parts in an disassembled view, right??
    Last edited by MarkHL; 08-25-2006 at 08:09 PM.

  9. #9
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    Good Questions!

    Some answers:
    First off, the electronic source for most of this is at cannondale.com, specifically on the tech page for Leftys:

    http://www.cannondale.com/tech_cente.../en_lefty.html

    2005 Lefty Max 140 Owner's Manual Supplement - this is the full 140 Max Manual
    http://www.cannondale.com/Asset/iu_f...140_EN_web.pdf

    2002 Headshok Lefty Max & Jake Owner's Manual - the 130 Max Manual
    http://www.cannondale.com/Asset/iu_f...er/0114864.pdf

    2004 Headshok Lefty Max & Jake Seal Kit Tech Doc - this is the one in Pic2
    http://www.cannondale.com/Asset/iu_f..._Kit_QC685.pdf

    I have a few more, like "how to mount the Lefty speedo adapter" and a parts breakdown of the hub. I think they are still up there, but in other locations. Look at all the Lefty pages, its worth the time.

    In the CarbonLefty Apart (Pic3) the parts actually are mostly where they belong (wow - did I actually plan that? Cool) except for the clip/bushing/race retainer which should be near the lower end of the upper.

    The seal housing: When you pull out your spring and look inside - you are looking at it. It screws into the top of the lower, and the bottom of the spring sits on top of it. The rebound shaft can be pushed out from the top and will come out the bottom of the lower. You need the extension to reach down inside the upper. I think you said this, but...

    In Pic3, the seal housing is between the bearing strips and the lower clamp - and yes, the seal is in a groove on the inside. When you look at the Max/Jake seal kit doc (116071.pdf) shown in Pic2 - you can see a cutaway - quad seal would go where item#2 Oring is pointed out. And actually, the second page of the doc talks about this - look at the upper right diagram "location of ORing inside.."

    And Hey! Here's a pic of a complete 140 seal kit. KF225 is the part number. IIRC, about $5 from my LBS - ordered from CDale.
    Attached Images Attached Images
    This isn't a "you're doing it wrong" topic.

    WSS/OSS: Open Source Sealant

  10. #10
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    Quad Seal Replacement complete

    I did the quad seal upgrade tonight, it took about an hour.
    1) I had to bolt the fork back on the bike to break the nut assembly loose, I did not want to risk crushing the fork tube, damaging threads, or screwing up the spindle by using a vice. The lefty fork (non-carbon) is easily removed and reinstalled on the bike using three mounting screws
    2) Bleeding the lower chamber after refilling it is essential... inflate the bladder until it takes shape, then slowly insert the assembly and let the oil overflow, be careful not to let any air back into the assembly
    3) Getting the o'ring out is a bit tricky, make sure you don't use a tool that will scratch the seating surface, I used a plastic dental pick, still it took a few minutes. Rather easy to put the new seal back in... After gettting the fork reassembled, if felt like new... Lot's of adjustable rebound, no knocking sound when I lifed the front end and repeatedly dropped the front wheel on the floor from several inches up. I took it out for about a 90 minute ride and it worked really well. Quiet with no top out sound, or clunking and... no hydraulic oil on the lower assembly under the boot after I finished.
    Final thoughts, is it's pretty cool to have a fork that can be maintained (i.e., disassembled and reassembled) by the owner with normal tools.

  11. #11
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    YOU: Very helpful...CANNONDALE: Not

    Hi, I followed your instructions to reinstall the bearing races, and I destroyed the set of bearings, but that was my fault (pilot err). So I purchased new set races from LBS and proceeded to start all over. I found that a large o-ring (1.50 ID x .125 W) holds the bearings races better than a rubber band. The o-ring will “index” onto the ridges on the bearing races, and you can more precisely get the bearings centered and aligned. I used a small diameter piece of foam insulation instead of the plastic caps that you used for the outer races. After I pushed everything together, one of the races was sticking out farther that the others. So, what I did was to stack two old credit cards together to protect the lower raceway, and I forced the outer race into alignment to the others by tapping with a hammer and a screwdriver. It sound drastic, but after trying to get all of them to align closely the first time, which lead me to destroy my bearings, it worked. I tried to use the large retaining nut to push the outer race back into place, but that did not work. So, I used the tap hammer method, and tapped the outer races back where they needed to be. I used the Lefty manual to check the overall fork length, and it was defiantly longer than when I started, but within the dimensions shown; well now my fork boot seems to be too short. So what could I have done wrong? The fork seems to work fine.

    I e-mailed Cannondale to find out if they had any instructions for a lefty rebuild and bearing reassemble, and their reply:

    looked into this for you and unfortunately at this time we do not have a manual and/or detailed instructions on replacing the O-ring seals on the Lefty Max 140 cartridges. It is advisable just to get another cartridge, versus the time put into replacing the seals. Heather Egolf

    My Reply:
    Heather, do you know cannondale products? The lefty 140 Max HAS NO CARTRIDGE. The shock's parts are assembled into the body of the shock. So would you want me to go to my bike shop and buy a new Lefty 140Max shock/fork assembly (~$1100+) just because of a lousy leaking o-ring? Please!

    Her Reply:
    Whoops, I meant the damper assemblies, which I may still refer to as a cartridge. You can replace the damper assembly, no need to replace the entire fork. Now, if you mean the quad seal, it can be replaced. You can contact our Tech Support at 1-800-BIKE-USA for further assistance. Heather Egolf

    WHAT AN EFFIN NUCKLEHEAD…..

    Thanks for your instructions, Very helpful!

    PS: I had a Cannondale Fatty fork and rebuilt that one several times. It was different; I used an old inner tube as a bearing guide. It was tied off each end, and when inflated, it pushed the bearings onto the walls of the fork body.

  12. #12
    All Lefty's, all the time Moderator
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    Quote Originally Posted by fansaldi
    I e-mailed Cannondale to find out if they had any instructions for a lefty rebuild and bearing reassemble, and their reply:

    looked into this for you and unfortunately at this time we do not have a manual and/or detailed instructions on replacing the O-ring seals on the Lefty Max 140 cartridges. It is advisable just to get another cartridge, versus the time put into replacing the seals. Heather Egolf

    I believe this is what I was getting at a few weeks back, with my post about the "new" Cannondale. Exactly.

    Wadester, excellent, now I don't have to do it, but I ay anyway, just cause some folks don't like having to search= One thing, the bearing/race reassembly is made alot easier if the outer races are installed in the upper slider. Hold them in place with an inner tube, cut and tied at both ends, insert, and inflate.Apologies to Sanfaldi, you mentioned this too, but in reference to a headshock, this will in fact work for any Cannondale system, just needs to be longer for Leftys!
    This is a Pugs not some carbon wannabee pretzel wagon!!

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  13. #13
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    Quote Originally Posted by MendonCycleSmith
    I believe this is what I was getting at a few weeks back, with my post about the "new" Cannondale. Exactly.

    Wadester, excellent, now I don't have to do it, but I ay anyway, just cause some folks don't like having to search= One thing, the bearing/race reassembly is made alot easier if the outer races are installed in the upper slider. Hold them in place with an inner tube, cut and tied at both ends, insert, and inflate.Apologies to Sanfaldi, you mentioned this too, but in reference to a headshock, this will in fact work for any Cannondale system, just needs to be longer for Leftys!
    Thanks Craig. I will look forward to seeing your writeup of this! I can see that the races-in-upper-with-innertube would work well. I know that once you get the bearings started in between the races everything is held tight anyways.

    Does the innertube method help prevent bearing pinch? My method seems to be very sensitive to this - requiring a finessed "wiggle" as you mate the assemblies.
    This isn't a "you're doing it wrong" topic.

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  14. #14
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    Checklist

    Hi - great well written info.

    Could one of you guys who has done it post a checklist of all the things you need to make the quad seal upgrade.

    Blown though mine in the first season (2005 lefty max tpc bought in 2006)

    i.e. 22mm socket, 19mm socket, Oring kit KF225 etc etc - and also what oil/grease.

    I guess mine could be a warranty job (bikes 6 months old) but I want to have tools/oils etc to do it myself as need.

    Also would it make sense to do change the new 4 lip seal yearly to prevent getting oil everywhere?

    I know all the info is their, perhaps I am being lazy but I guess a check list would also help to make it clear for first timers like me.

    Thanks
    Last edited by dusttrails; 09-24-2006 at 10:57 AM.

  15. #15
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    List?

    Quote Originally Posted by dusttrails
    Hi - great well written info.

    Could one of you guys who has done it post a checklist of all the things you need to make the quad seal upgrade.

    Blown though mine in the first season (2005 lefty max tpc bought in 2006)

    i.e. 22mm socket, 19mm socket, Oring kit KF225 etc etc - and also what oil/grease.

    I guess mine could be a warranty job (bikes 6 months old) but I want to have tools/oils etc to do it myself as need.

    Also would it make sense to do change the new 4 lip seal yearly to prevent getting oil everywhere?

    I know all the info is their, perhaps I am being lazy but I guess a check list would also help to make it clear for first timers like me.

    Thanks
    First off, I bet that you will find an ORing, not the quad. I'd figured they went quad with the 140, but mine had the O - which blew. I'm keeping a spare seal kit on hand, but not planning on regular replacement.

    Tools: Go download the manual - it gives most of this (except the seal retainer cap)
    5mm allen to undo clamps/brakes/wheel
    ExtBB tool to take off the top cap
    19mm & 9mm openend wrenches to take off the top assembly and get the spring out
    22mm (TPC/FFD) or 24mm (SPV) to take out comp damper
    19mm socket + 8"extension/ratchet to unscrew cap
    Oil: Golden Spectro cartridge fork fluid 85/150 (got mine thru BTI/LBS)
    Grease: Royal Purple Ultra Performance Grease/ I use FinishLine teflon fortified grease
    This isn't a "you're doing it wrong" topic.

    WSS/OSS: Open Source Sealant

  16. #16
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    As an info on quad seal.

    The Super Fatty that came with my 1FG has an integrated air chamber wich are no longer removable,and are bigger in diameter. It' got a quad seal in it. Works fine so far.
    "There is a big difference between kneeling down and bending over" -FZ

  17. #17
    All Lefty's, all the time Moderator
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    Quote Originally Posted by wadester
    Does the innertube method help prevent bearing pinch? My method seems to be very sensitive to this - requiring a finessed "wiggle" as you mate the assemblies.

    It does not really help prevent it, it just allows for an easier overall re-assembly. I can't recall if you mentioned this, but regardless of methodology, you want 11 bearings above, and 11 below the inner steerer. The pinch is best prevented through very careful wiggling upon reinstalling.
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  18. #18
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    Nice one - thanks very much

    Have ordered the Oring kit last week - will have to see which one I get

    thanks again

  19. #19
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    Thanks for a great thread. In the lefty supplement manual I was looking at the parts available and there are a number of inner race thicknesses. How would one go about selecting the proper thickness for the inner race?

    Thanks,
    Jim

  20. #20
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    Quote Originally Posted by jimpad
    How would one go about selecting the proper thickness for the inner race?
    First of all, all the outer races will be the same thickness, but those thicknesses vary. The inners can be all diiferent from the neighbors, so take them one at a time, leaving the others in place. Use a micrometer that does English (non metric). .021, .022, .023, etc.
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  21. #21
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    I think I understand. Will all the inner race thicknesses be the same within the same fork?

  22. #22
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    Quote Originally Posted by jimpad
    I think I understand. Will all the inner race thicknesses be the same within the same fork?

    No, the outers will be the same thickness, but depending on the fork, those may be of a few different thicknesses. The inners in a given fork, may all be different from one another. Most frequently only one or two will be different though. Gotta mic them all though, to be sure.
    This is a Pugs not some carbon wannabee pretzel wagon!!

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  23. #23
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    Selection criteria?

    Quote Originally Posted by MendonCycleSmith
    No, the outers will be the same thickness, but depending on the fork, those may be of a few different thicknesses. The inners in a given fork, may all be different from one another. Most frequently only one or two will be different though. Gotta mic them all though, to be sure.
    OK, so the outers are all identical on a unit - but do come in different sizes. So the upper/outers will be symmetrical, and the thickness used will be based on the ID of the upper. Any "magic" distance race-race inside?

    The inners are all different, or matched across? Same Q?: Any "magic" distance race-race outside?
    This isn't a "you're doing it wrong" topic.

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  24. #24
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    Quote Originally Posted by wadester
    OK, so the outers are all identical on a unit - but do come in different sizes. So the upper/outers will be symmetrical, and the thickness used will be based on the ID of the upper. Any "magic" distance race-race inside?

    The inners are all different, or matched across? Same Q?: Any "magic" distance race-race outside?

    You would think so, but the answer is more nebulous. This difference in inner race thickness comes from a real world issue, over which there is little control. The outers are made in a fashion that allows there to be a high level of consistency. The inner steerer experiences changes in thickness due to machining tools getting out of tolerance over the course of weeks of production. By using variable thicknesses it allows them to maintain proper bearing preload, much less exspensively than re calibrating tooling every week or two. The rule for bearing preload is, extend the fork all the way up, and put a weight on the top of it. The steerer must drop with between 2 to 4 pounds on it, More than 4 lbs? Races are too thick, less than 2 lbs, races are too thin. Then, mic across the 2 inner axis's, take the thinner of the 2, measure their races, and replace the thinner of the two, with the next thicker. And so on, and so on. Have fun!
    This is a Pugs not some carbon wannabee pretzel wagon!!

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  25. #25
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    OK, if it's not already evident by my questions... I've disassembled my fork without noting race positions. So, if the races are selected to provide proper preload (and not concentricity) would it be reasonable to say the inner races will either all be the same or they should be paired ie. if not all the same thickness will two be the same and the other two the same? If so, it seems I should assemble the telescope such that a large inner race will be opposite a small inner race and the same for the other two?

    Thanks for the help.


    You would think I wasn't even reading your responses, well after rereading I've got it now. Ignore this one.

    Thanks again,
    Jim
    Last edited by jimpad; 10-21-2006 at 05:56 PM.

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