Fox van rc problem

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Fox van rc problem
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flag VorsprungSuspension
Posted: Apr 17, 2014 at 23:28 Quote
BryanBobo wrote:
Ever figure out what the issue was here? I am having an issue with my Van Rc as well (not sure if its the same). But when I step off my bike and press down on my seat I get a small hitch before the bike moves through its travel.

This issue is commonly caused by a small circlip between the compression base valve and the reservoir bridge breaking or wearing. Because the compression base valve sees fully reversed cyclical loading (sometimes it's being pushed one way, sometimes the other) and its location in the shock is highly dependent upon manufacturing tolerances being perfect, over time the assembly slightly wears on its seat in the bridge. The nitrogen charge in the shock pushes the assembly out of the body when the thing is at rest, but as soon as you compress it, the oil flow pushes it in the opposite direction, and if there is any play in there, the thing will move.

In order to fix it, the shock needs to be fully rebuilt and either the reservoir bridge replaced (once the circlip breaks once, it'll happen again as it very quickly causes more wear on the bridge) which is needlessly expensive, or an appropriate spacer inserted to take up the space. If it's still under warranty, I recommend sending it to Fox with a note saying the compression assembly is moving in the bridge. You can often feel it by putting your finger against the blue compression knob whilst bouncing on the bike.

Steve
flag mwilliams
Posted: Apr 18, 2014 at 0:41 Quote
Don't need to rebuild it to check nitrogen
. I rebuilt my myself and got a mx shop to recharge it.
Just take it into a mx shop and ask them to check the pressure and recharge if necessary.
flag BryanBobo
Posted: Apr 18, 2014 at 5:46 Quote
VorsprungSuspension wrote:
BryanBobo wrote:
Ever figure out what the issue was here? I am having an issue with my Van Rc as well (not sure if its the same). But when I step off my bike and press down on my seat I get a small hitch before the bike moves through its travel.

This issue is commonly caused by a small circlip between the compression base valve and the reservoir bridge breaking or wearing. Because the compression base valve sees fully reversed cyclical loading (sometimes it's being pushed one way, sometimes the other) and its location in the shock is highly dependent upon manufacturing tolerances being perfect, over time the assembly slightly wears on its seat in the bridge. The nitrogen charge in the shock pushes the assembly out of the body when the thing is at rest, but as soon as you compress it, the oil flow pushes it in the opposite direction, and if there is any play in there, the thing will move.

In order to fix it, the shock needs to be fully rebuilt and either the reservoir bridge replaced (once the circlip breaks once, it'll happen again as it very quickly causes more wear on the bridge) which is needlessly expensive, or an appropriate spacer inserted to take up the space. If it's still under warranty, I recommend sending it to Fox with a note saying the compression assembly is moving in the bridge. You can often feel it by putting your finger against the blue compression knob whilst bouncing on the bike.

Steve



I will add that the "hitch" is very veryyy subtle. I feel that most would probably not even notice it. Basically my main fear is that it is something minor that doesn't really require a rebuild. Unfortunately, I don't have the resources or knowledge to rebuild it myself.

Thank you for all the pointers though, absolutely some good things to keep in mind and look at when I take it off the bike.
flag jonbikes
Posted: Apr 18, 2014 at 5:57 Quote
Take the shock off the bike, take the coil off the shock and compress it by hand, that should give you a pretty good indication as to what the shock is doing. I still vote for the leverage ratio curve of the frame.
flag ka81
Posted: Mar 15, 2023 at 15:10 Quote
ANyone, please: what the official air pressure in IFP chamber for Fox Van RC 2012 ??
Is it the same ( 300 PSI ) as it's said for 2018 https://www.ridefox.com/fox17/help.php?m=bike&id=869 ??
flag mior
Mod
Posted: Mar 15, 2023 at 15:15 Quote
ka81 wrote:
ANyone, please: what the official air pressure in IFP chamber for Fox Van RC 2012 ??
Is it the same ( 300 PSI ) as it's said for 2018 https://www.ridefox.com/fox17/help.php?m=bike&id=869 ??
im 99% sure all van rc/bomber cr's are 300
flag M0rd4c4i
Posted: Mar 16, 2023 at 14:53 Quote
@ka81 if you search using the 4 digit code or serial number you should find all the relevant information you need.
flag ka81
Posted: Mar 16, 2023 at 22:25 Quote
M0rd4c4i wrote:
@ka81 if you search using the 4 digit code or serial number you should find all the relevant information you need.
if I have that 4 digit code or serial number on a shock - yeah, I would..
flag M0rd4c4i
Posted: Mar 17, 2023 at 1:56 Quote
Ah, that makes things more difficult as they don't allow you to search tech docs by model and year.

Only option I can think of left is to email FOX then and ask them to forward you links then.
flag ka81
Posted: Mar 17, 2023 at 6:14 Quote
M0rd4c4i wrote:
Ah, that makes things more difficult as they don't allow you to search tech docs by model and year.

Only option I can think of left is to email FOX then and ask them to forward you links then.
C'mon, man, seriously?..
Email tgem? You know any particular email of real FOX tech/support departments, that actually would/could answer/help usual owner ?!..

As for info:
Search by model and year -
https://www.ridefox.com/fox17/help.php?m=bike&listall=service
&
https://www.ridefox.com/fox17/help.php?m=bike&listall=partlist
Unfortunately, no 2012
flag M0rd4c4i
Posted: Mar 17, 2023 at 6:47 Quote
Look under contact and find the service locations with email contacts listed, no guarantee they'll respond or give you the information your seeking but presently you're working in the dark.
flag ka81
Posted: Mar 17, 2023 at 13:50 Quote
well, anyway, if anyone here knows the answer - write, please.
Thanx !
flag mior
Mod
Posted: Mar 17, 2023 at 13:59 Quote
ka81 wrote:
well, anyway, if anyone here knows the answer - write, please.
Thanx !
iirc all fox van rcs take 300 psi +/- 10 (from fox site) if you want 100% certainty find one for sale and use that 4 digit id.
flag ka81
Posted: Mar 17, 2023 at 14:25 Quote
mior wrote:
ka81 wrote:
well, anyway, if anyone here knows the answer - write, please.
Thanx !
iirc all fox van rcs take 300 psi +/- 10 (from fox site) if you want 100% certainty find one for sale and use that 4 digit id.
gracias.

p.s. any Fox Van RC 2010-2012 owner - write down here your 4-digit number, please.. )
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