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Discussion Starter · #1 ·
I've got an '06-'07 Fox 40 that was sent back to Fox for a rebuild. They replaced the stanchions and the sliders and installed the proper spring for my weight. I know it's not oversprung, I'm weighing in around 300 lbs right now, and I know they don't have a spring rate that high. I'm currently running HSC and LSC all the way open, and there is still too much damping. The LSC actually feels pretty good the way it is, but there is way too much HSC still. It's destroying my hands and arms when I ride. So, has anyone had any experience with this? What have you done to fix it? I'd totally be down to send the fork off to a tuner that could take care of it. :thumbsup:
 

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Discussion Starter · #3 ·
Call Fox and politely explain the issues you are having, and that your fork was just serviced by them. I'm sure they'll take care of you.
There is a problem with that, it's been well over a year since I had them do the work. I hadn't ridden the bike with the refreshed suspension until recently. I could still try that approach though.
 

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There is a problem with that, it's been well over a year since I had them do the work. I hadn't ridden the bike with the refreshed suspension until recently. I could still try that approach though.
Worth a try, but I'd expect to pay for an overhaul if you send it in.

Something is definitely amiss though. At your weight you shouldn't have the LSC and HSC backed out all the way. Do you ever get full travel?
 

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No, I think 7" was the most I got out of it. That's what the wipers to the line of dirt/mud on the stanchions measured.
Somethings not right here.

The FOX 40 RC2 and the FIT cartridges come stock with 10wt oil. It might be possible that the service tech working on your fork might have "bumped" it up to a 15wt because of your size (call Fox and ask).

Anyways, to help with your harshness issue, you can change to a lower viscosity oil inside the cartridge - say to 7.5wt or even down to a 5wt (again, check with FOX first to see what they put in). Additionally, you have an option ( on the RC2) to decrease your ending stroke compression by rearranging the spacer stack on the compression assembly.

Before doing the above, I would first remove the cartridge from the fork and check to see if it binds or locks out while cycling it up and down. You could have something broken internally, or the cartridge could have too much oil in it ( which I doubt).
 

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Discussion Starter · #7 ·
Thanks, I may pull it apart myself. I'd rather send it off to someone, but it seems like there is a strong possibility that I may have to pull it back apart and play around with oil weights and maybe the shim stack.
 

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The FOX 40 RC2 and the FIT cartridges come stock with 10wt oil. It might be possible that the service tech working on your fork might have "bumped" it up to a 15wt because of your size (call Fox and ask).
To add to this, Fox recently changed their spec fluid from Torco to Silkolene, the Silkolene is quite a bit heavier than the old standard.
 

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So, has Fox changed the valving to compensate?
No idea.

I have a 2008 40, and had a similar issue after rebuilding the damper with Fox's new Red fluid. No way to tell if your issue is fluid wt. related, but something to consider...

Bottom line, you, or someone else, need to get inside that fork to make sure nothing is damaged, and that re-assembly is done correctly. After that is done, verify what weights of fluid are used, what weight spring is actually in there, and make note. From there you will have a base for tuning.

Fox's service tutorials:
WebHelp
 

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Likely not the problem, but have you ensured the fork is aligned and not pinched or splayed at the axle fitting?

How does the fork feel when pushed when not riding, is the seal drag spiking the feel?

Yes it may be damaged, or possibly the oil is thicker, but I would look for simple stuff first.

Also, FWIW, if you are that large, how is the rear end sprung and working. If the rear is squatted the fork won't work well. Also, if the bike runs a choppered head tube angle, this will add force into the steering and load your wrists with each small deflection of the front tire.

All the best and hope it is easy to resolve.

PK
 

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Discussion Starter · #13 ·
Likely not the problem, but have you ensured the fork is aligned and not pinched or splayed at the axle fitting?

How does the fork feel when pushed when not riding, is the seal drag spiking the feel?

Yes it may be damaged, or possibly the oil is thicker, but I would look for simple stuff first.

Also, FWIW, if you are that large, how is the rear end sprung and working. If the rear is squatted the fork won't work well. Also, if the bike runs a choppered head tube angle, this will add force into the steering and load your wrists with each small deflection of the front tire.

All the best and hope it is easy to resolve.

PK
I took all the preload out of it, along with the compression, to try to get it to feel better, and it feels pretty good at a stand still. I try to stay pretty centered on the bike, like I would on my motocross bike. I have a 700 lb spring on the rear, and it feels pretty balanced. It definitely gets worse at speed with constant stutter bumps, almost like it's packing down from too much rebound. I guess if it had heavier weight oil in it the rebound would be affected too. I'll check over the clamps, the axle, and the pinch bolts, but I'm pretty sure that's all right.
 
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