Rockshox Motion Control Spring

[Two-Stroke]

Does anyone have experience with a Rockshox Poploc not releasing?

 

Fork is a Rock Shox Reba 29 RL Air (2012 model). Here's the Motion Control unit model: http://www.sram.com/rockshox/products/remote-upgrade-kit-poploc

 

The fork doesn't unlock when pushing the Poploc button. The remote mechanism and cable both move freely. I also removed the Motion Control unit from the fork to check that it's spring was attached top & botton, and that the bottom aluminium disc/value was rotating freely.

I testing the spring action without cable attached after reassembling the fork and the action feels correct.

 

Any ideas why it doesn't release with the Poploc? Could the Motion Control unit's spring have weakened? I'm stumped.

[Hilton.]

I've had the same problem with my Reba for a while now. I have a 2013 Reba RL Solo air.

 

I haven't gone into detail with the problem yet, so I've just left it in fully open mode for the moment.

I'd also be interested in a response to this problem. I'm sure the remedy is fairly simple.

[David Marshall]

When I do this type of work I always like to check the operation of the fork first. That is check that the lockout is working by manually activating it. If it works then the oil level in the damper is ok. It must cover the foot of the damper cartridge. Next the cable and cable housing. If in any doubt replace. Lastly you may have dirt in the top cap. I mean between the part that turns the shaft and the top cap itself (there is an o-ring seal in there, which may also be damaged and causing friction).

 

To remove the topcap clamp the damper body in a tube clamp or failing this slide a 4mm allan key through a pair of the slots in the damper body to hold it while you remove the top cap with your 24mm socket. The cap loosens in a CLOCKWISE direction. You can now get at the seal and reset the spring if necessary.

 

Hope this helps.

[Two-Stroke]

Thanks for the advice David. Did everything except removing the damper's top-cap...was hesitant to go beyond my "level of knowledge". I'll give it another try this weekend and check out the o-ring seal. If it needs replacing, would it be a standard size (available over the shelf) or something I'd need to order from the LBS?

Edited May 20, 2014 by Diesel85

[David Marshall]

The o-ring is 1.8mm by 13mm (assuming it is the same as the older red cartridge). Best chance is from a bearing/seal shop. Not too difficult to do - just keep your wits about you. Observe the spring position and the way the spring shaft fits at the bottom. Check that it operates before you assemble the fork. In the unlikely event of you not getting it right contact Droo at Stoke and Suspension. He should also be able to provide the o-ring.

[David Marshall]

The o-ring is actually and imperial one 1.78mm X 12.29mm.

[Skylark]

As Dave mentioned the thread on the top cap to the plastic cart body is left handed - don't forget that!

I had the same issue , the shaft was slightly too tight/seized in the top cap, not sure why but that was the issue, so the spring didn't have the strength to overcome the friction when you press the pop lock button to release it. I cracked my cart body by thinking it was a right hand thread so I never got round to sorting the issue out but before that a drop of oil would loosen it up for a while and I was planning on reaming out the shaft hole with fine sandpaper, the shaft does not seal at the point, it seals well below that so you shouldn't introduce leaks by making that hole slightly bigger. My cart was from a 2009 RS fork but they all quite similar.

Edited May 20, 2014 by Skylark

[droo]

This is a pretty common issue with the spool type remote damper cartridges. The most reliable fix is to throw the cartridge away and replace with an XX MoCo cartridge - the hydraulic poploc is close to bombproof. Not a cheap option though, but will save you a whole lot of heartache on muddy rides.

 

A possible quick fix is to back out the screw that holds the blue cable spool on to the damper a quarter of a turn. Sometimes this screw gets overtightened and pushes the shaft against the topcap, causing it to jam.

 

Next would be to strip the damper as per David's instructions and clean out any gunk in the top of the assembly.

 

If you're out of your comfort zone, bring the fork to me and I'll sort it out for you, it's not an expensive fix.

[Two-Stroke]

Thanks for the input guys - muchas gracias!

 

Droo, I'll give you a shout if I get stuck...work down the road from your shop. If confidence exceeds skill level, I might come knocking next week to drop off a bag with bits & pieces of the fork