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Discussion Starter · #1 ·
I was noticing that my Lefty Max 140 TPC+ (I swapped in the TPC+ valving using advice on this forum and parts from MendonCyclesmith) sags a bit much. I am 205 lbs riding a Ninerbikes RIP9. I tried adjusting the preload to reduce the sag somewhat, but it seems a near-impossibility to thread the cap back on top of the tube against all that spring pressure.

I think I have the 'black' spring (does this refer to the color of the tubing over the spring?) which I am told should be about right for my weight. But it doesn't really seem to be quite enough.

Are there any tricks to getting some preload into this thing? How do you overcome the spring force to screw the cap back on against spring pressure?
 

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Hybrid Leftys aren't real
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Duncan1104 said:
If your having trouble re threading the top cap, you need to do a bearing reset. Here is a thread to do a bearing reset: http://forums.mtbr.com/showthread.php?t=212844[/url
As for the amount of sag you might want to go to the brown spring as baker said.
Everything he said, particularly the part about tough topcap reassembly, and the need for bearing reset! :thumbsup:
 

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Discussion Starter · #5 ·
I already read that thread, and thought I had followed the instructions for bearing reset. I removed the spring retaining cap at the top, pushed the fork down to the bottom of it's travel pretty hard, and then pulled it up to the top of it's travel, also pretty hard.

I noticed that at the bottom of the travel it felt like I was pushing against a spring. Maybe I was hitting the TPC+ oil bath and valving?

Anyway, I'll try it again.
 

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Hybrid Leftys aren't real
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Lifespeed said:
I already read that thread, and thought I had followed the instructions for bearing reset. I removed the spring retaining cap at the top, pushed the fork down to the bottom of it's travel pretty hard, and then pulled it up to the top of it's travel, also pretty hard.

I noticed that at the bottom of the travel it felt like I was pushing against a spring. Maybe I was hitting the TPC+ oil bath and valving?

Anyway, I'll try it again.
Nope, I dry ran that set up before I ever suggested it to anyone, so no TPC+ interference is happening.

Until the cap that the split rings fit into, is down inside the fork about an inch+, you're not done resetting. It's a bit cave man feeling when you're doing it, many folks don't approach it with enough zest:eekster: :thumbsup:
 

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Discussion Starter · #7 ·
MendonCycleSmith said:
Until the cap that the split rings fit into, is down inside the fork about an inch+, you're not done resetting. It's a bit cave man feeling when you're doing it, many folks don't approach it with enough zest:eekster: :thumbsup:
OK, you are right about that. It took quite about of yanking to get the top cap down inside the tube. Makes me think I had lost a couple inches of travel to bearing migration. I did get this Lefty used, so it has probably gone quite a long time withouth this important maintenance.

Anyway, the RIP9 is riding high in the front again. It is not nearly so easy to blow through all the travel now.

I have yet to take it out on the trail with the TPC+ damper and reset bearing migration. I imagine it will be a big improvement, but it is hard to tell just bunnyhopping curbs in the neighborhood.

I still think these Leftys might be a good application for a progressive-wound spring, but I'll have to reserve judgement until after a good rocky ride later this week.

Thanks guys. I guess it wasn't clear just how hard I would have to jerk that thing.
 

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Discussion Starter · #9 ·
belated test results

I thought I should reply back and comment on how the TPC+ conversion on a reduced-travel 140mm Lefty Max for 29er use worked out. That was a keyboardful.

I have ridden the bike quite a few times since the modification. I did not completely disassemble and rebuild the fork. It seemed like quite a bit was involved and I wanted to get out and ride it. I'm not sure it really needs it at this point in time.

After resetting the linear bearings, adding some preload, and installing the TPC+ damper (with cap from a regular TPC unit) I added some Golden Spectro 2.5W oil and rode the bike around the neighborhood. It still seemed soft. I turned up the compression and rebound damping.

Then I took it out on some rocky trails. That is where the correct settings were much more obvious. Hopping curbs and other obstacles in suburbia is useless when it comes to suspension adjustments.

I reduced the preload until there was an inch or so of travel before the shock "topped out". This kept the front wheel on the ground under most conditions. I found I had to reduce the compression damping to near the minimum, with the rebound damping about 1/3 from minimum. With these settings the front wheel felt smooth over fast rocks, but would rebound fast enough to get in contact with the trail again. An important feature around corners ;)

Anyway, thanks for the technical assistance on this complicated area of the bike. I am very happy with the results.
 
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