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The official Lefty thread, tech, mechanical, etc

448K views 1K replies 397 participants last post by  MendonCycleSmith 
#1 · (Edited by Moderator)
#202 ·
The travel reducers/limiters are positioned on the shaft above the damper. If you want to reduce the A-C length you need to place a spacer on the shaft below the damper. Cannondale doesn't make a specific kit for this and I'm not sure if the top spacer can be used for this purpose. They might have too big a diameter, but i guess they could be grinded down a bit if that is the case.
 
#204 ·
Yes that is correct. No you don't need to add any volume reducers to compensate. When you place it where you have indicated the volume will be reduced "automatically".

I myself just bought a Lefty Carbon Ultra PBR with 120mm travel to replace my Lefty Terralogic and plan to lower it to 110mm in the same way and get the AC of 480mm as the Terralogic. The new speed's with 100mm travel and AC of 470mm I fear are simply too low and fast steering for my kind of riding.
 
#206 ·
Just one last comment. The reducer clip can be placed in two ways on the lower shaft. If placed below the lower air seal you will increase the volume of the negative air chamber. Placed above it will remain the same. I don't know how much it will effect the feel of the suspension, I'll try to experiment with it myself.
 
#207 ·
Hm, you mean it is possible to attach the limiter either in position 1 or 2:



I have doubts that attaching the limniter in position 2 would have a significant influence on negative air spring volume since the limiter is solid and has a volume itself. Moreover I would have concerns that the negative air spring still works correctly.
 
#208 ·
Yes exactly and you a right in that the effect is minimal. But please be carefull with the width of the clip. The inner diameter of the lower leg is smaller than at the top. You don't want it to wear on the inner surface. To be sure please compare the diameter of the air seal and the clip.
 
#209 · (Edited)
ssuats, I just received my fork and put the spacer in position 1, as you indicated in post #207. Just one comment though. The travel reduction spacer is about 0.5mm larger in diameter than the upper air seal and you need to file it down or it won't go down the lower leg. It's a one minute job. Besides this it went as smooth as expected, though the locktite on the damper was very hard to break free. You need a lot of force to get it loose and be very carefull that the castle tool doesn't slip out of the damper interface or you will be in trouble. My fork was originally 490mm A-C now it's 480mm and you can definitely feel the different in steering, but I don't notice any change in suspension feel at least on tarmac.

EDIT!

I just realized that placing the spacer in the position indicated above will cause the spacer to move on the damper shaft when the fork is compressing which might cause wear on the surface in the long run. I have revised the placement to now be between the lower bottom out bumper and the lower air seal. The spacer should not move when place in this position.

 
#210 ·
Possible Lefty Problem

The quick version - have a 2011 Ultra PBR. It's seen use, but not a ton, and hadn't even been on a frame for several months. Recently I picked up a frame for it, and before installing, figured I better do the bearing reset, as I had not done it before. Did that, one ride, no problem. Last Sunday did a rough, fast race. Last night I noticed quite a bit of suspension fluid on the bottom part of the Lefty, from the boot down. It wasn't so bad that it was dripping on the floor, but that section of it was pretty much covered. This is one of 3 Lefty's I have and this is new on me. Did I blow something during the race? Cause for concern? (I'm assuming so, but...) Any ideas or tips for me here, other clues to look for, etc? Thanks!
 
#213 ·
The quick version - have a 2011 Ultra PBR. It's seen use, but not a ton, and hadn't even been on a frame for several months. Recently I picked up a frame for it, and before installing, figured I better do the bearing reset, as I had not done it before. Did that, one ride, no problem. Last Sunday did a rough, fast race. Last night I noticed quite a bit of suspension fluid on the bottom part of the Lefty, from the boot down. It wasn't so bad that it was dripping on the floor, but that section of it was pretty much covered. This is one of 3 Lefty's I have and this is new on me. Did I blow something during the race? Cause for concern? (I'm assuming so, but...) Any ideas or tips for me here, other clues to look for, etc? Thanks!
You certainly blew the rebound cartridge. Try locking your lefty again. It shouldn't be working anymore. It happened to me twice on my 2004 lefty carbon. (every 3 years is not so bad, i think!)
The bad thing is, most shop don't replace them themselves, they send it back to Cannondale for tune up and so you're left waiting 2-3 weeks for your fork to come back!!!

JF
 
#211 ·
Differences in the New 2013 Lefty Fork?

Can anyone summarize and explain the new features for 2013 in the high-end 29r carbon fork? I'm a Lefty newb, but convinved the design is better. I am trying to figure out if is worth to wait till mid-Fall for a 2013 or score a deal on a 2012.
 
#212 ·
Can anyone summarize and explain the new features for 2013 in the high-end 29r carbon fork? I'm a Lefty newb, but convinved the design is better. I am trying to figure out if is worth to wait till mid-Fall for a 2013 or score a deal on a 2012.
I'd wait for the 2013 because of new features (but nobody knows yet if there we will be any issues with these lefties :) )
for me the best new update is auto bearing reset or possibility to reset without disassembling the lefty - this worth a lot.
 
#214 ·
Thanks. I tried it, and the lockout seems to still be working. I raised the boot up and there is definitely fluid. And it couldn't be just the grease from the square slider part (technical terms here.) Thinking I should probably just get a general tune done anyway and then anything wrong can be fixed while they're at it.
 
#221 ·
xlr issue

my xlr lefty on my scalpel behaves differently all of the sudden, here are the things i notice different:

1. after removing all the air from it, it is not soft to compress and decompress not like before that it was soft and smooth to cycle after taking all the air out

2. putting only 100psi makes it feel like its locket out

3. increasing rebound(turning clockwise) makes it hard to compress the lefty but does not slow down the rebound

does anyone have experienced this? i felt like there's trapped air inside but im pretty sure i depressed the schrader valve to take all the air out

bike is 3 months old, 2012 scalpel 2
 
#222 ·
my xlr lefty on my scalpel behaves differently all of the sudden, here are the things i notice different:

1. after removing all the air from it, it is not soft to compress and decompress not like before that it was soft and smooth to cycle after taking all the air out

2. putting only 100psi makes it feel like its locket out

3. increasing rebound(turning clockwise) makes it hard to compress the lefty but does not slow down the rebound

does anyone have experienced this? i felt like there's trapped air inside but im pretty sure i depressed the schrader valve to take all the air out

bike is 3 months old, 2012 scalpel 2
Try adding some fox float fluid to the air chamber (that's on the bottom). I think that will fix it.
 
#227 ·
Hi all,

After years of lurking and dipping in and out of mtbr for help and guidance the time has come to step out of the shadows. I'm now (as of today) the very proud owner of a CD Jekyll with the ubiquitous Lefty, in reality i'm the proud owner of a Lefty with a bike attached, atm, though i'm sure once its all up and running i'll be the afore mentioned.

I had previously (and still do) a Whyte JW-2, similar to the PRST-1 but lower specc'd as standard, so i'm a bit of self confessed nut of all things weird and wonderful in the mtb world! I've always admired the Lefty and HAD to have one. Saw one in the free-ads and took a punt, it was frickin miles away so i did what any self respecting man would do with his hard earned cash and bought it over the phone having only asked the bare minimum of information, needs must and all.

I got it for a good price on the basis that the fork needed a service. I've scoured the net and managed to glean the following: its an OSS100 model DLR, i believe to be a 2000 model, though its difficult to get accurate drawings to identify from and there doesn't appear tp be much useful info on the bike, i can post pics (i think) if anyone is still reading this.

I'm an engineer by trade, specifically a design engineer, whilst i do spend most of my time at a computer i do get my hands dirty and have what i would consider to be a high level of mechanical aptitude, plus access to all kinds of fun toys for making bits/tools as needed.

Every link i've found to 'service manuals' for a lefty have taken me to the Cd website and a dead link, the old guy in overalls (who i'm guessing is Gerd Schraner, anyone?) clutching a wheel and looking forlorn is becoming quite a familiar sight now. I've managed to glean that my Lefty is one of the first fully servicable units, not the very early press-install units (2.0) and i can see how i think its should come apart but i don't want to break anything trying.

Should the 90 degree lower leg (which i believe to be Ti, though it doesn't actually say so) come off the lower end of the stancion? There's what looks like a set screw to hold it on, which once removed should allow the removal of the 90 degree section with the axle stub, then allowing the cartridge to be passed out through the top of the steerer (handle bar end)?

Another quicker question, will all Lefty hubs fit all Lefty's? My hub is the original Coda with 4 holes for mounting the disc, can i fit a later 6 hole disc mount hub? Sorry to be pendatic but if the answer is no, could anyone explain why its no, if its just a case of offsetting the disc mounting face or some other mis-alignment that can be addressed?

Many thanks to anyone that made it this far, i tried to set-up a new thread but i've not posted enough.
 
#230 ·
I'm hoping I didn't make an expensive mistake...I have 2011 Cannondale Trail sl2 29er and just purchased a 2012 pbr lefty off of ebay. Clamp spacing wasn't specified but he did mention the bike was too small and he was parting it out. So with that I assume its the regular clamp spacing. My bike has the 1.5" headtube and I'm not sure whether I need to run the SI headset or if the bearings will press in the frame like the flash. The headtube I believe is 4.5" (I say believe as its measures 5" but it appears to have a cup pressed into the bottom of the tube. Cannondales specs for the 2012 says 4.5". Do you guys think the regular clamp spacing will work? If so what headset will work? Thanks...I'm sweating bullets over here hoping I didn't just waste a bunch of loot lol....
 
#232 ·
Lefty rebound knob/lockout not working

So my lockout lever has no effect, and the rebound knob just unscrews. I don't have a fluid leak. Does anybody know what could cause this and how to fix it? I know if I send it to Cannondale they'll just charge me $260 for the new PBR damper.
 
#233 · (Edited)
swapping Lefty for old DD50

Regarding headset bearings, if I pop the DD50 out of my Super V and leave the bearings in the head tube, can I just pop the Lefty right in, or do I need to transfer the Lefty bearings into the Super V head tube? And, does a Lefty pop out just like a DD50? I've had the DD50 and other HeadShok forks out, but never a Lefty. On the DD50, I just smack the top with a deadblow hammer and it comes right out.

EDIT: I'm not sure I'm supposed to reply to my own posts, so I'm just putting in an edit.
Yes, the old DD50 bearings are the same as new Lefty bearings, and the Lefty just popped out of the headtube with a few smacks of the deadblow hammer once the top mounting bracket was removed. And since I have a regular stem and not one of the new one-piece ones, everything just swapped over.

Thanks,

Andy B.
 
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