Poploc on new Reba giving hassles

[mongoose_dude]

Hi

I got a new Rock Shox Reba (Race) about a  week ago. The thing has poploc remote lockout. Problem is: when I lock the fork and put some weight on it (even just me sitting on the bike), then the poploc doesn't want to release properly. So - when you unlock the poploc on the handle-bar, it almost seems as though the spring that's supposed to return the shock to its unlocked state is not strong enough. The lockout only releases VERY sluggishly, and only unlocks all the way when you take all weight off the front of the bike.

 

What I have done:

> Checked that there is no dirt in the lockout mechanism mounted at the top of the crown

> Oiled the cable of the poplock mechanism properly and made sure that there are no kinks in it

> Made sure that the mount at the top of the crown is not obstructing the cable in any way

 

Any ideas? Can one wind the "return" spring on the inside of the shock tighter? What else could be a reason why the poploc doesn't want to release properly.

 

Would REALLY appreciate some advice / ideas. A bit worried...

[Johan Bornman]

Next thing you have to do is determine if it is the cable/remote lock or the internals.

 

Remove the cable from where it enters the fork. See if the lockout is now completely disabled and, if you can (with force and strong fingers) freely rotate the poplock mechanism on top of the fork. It has a strongish spring, so expect some resistance. However, it should be a smooth movement about 3/4 of one revolution (approximately, I don't have one with me right now). If all of that is OK, move on to the cable mechanism. Now that is is free of the fork, see if it moves freely.

 

Fixing the cable is obvious - find the kink/crud/fray.

 

Fixing the poplock is not obvious, but report back here and we'll guide you to the next step.

 

[mongoose_dude]

Thanks for your reply!

 

I have already removed the cable and the poplock mechanism does rotate freely. The movement of the mechanism is totally smooth. I did notice, however, that its spring is not as strong as the one on my previous fork (a Duke Race with poplock). Could this be the reason for why the thing is not releasing properly?

 

I still need to check whether the poploc mechanism rotates freely under load (with the cable off), but I am unfortunately not with my bike at the moment. Will report back on that asap.

[Goodbadugly]

If cable friction is your problem, try a thicker gauge sleeve like those for the brake cables.

[mongoose_dude]

Hi guys... So I've checked things again carefully, and it seems that the issue is not related to cable friction / kinks.

 

I took of the cable entirely, then locked the shock by turning the mechanism with my hand, then put weight on the fork and let go of the mechanism. What happened is that the mechanism did not release as long as I kept weight on the fork. When I took all the weight off, the mechanism moved back to the "unlocked" position. So - it seems as though the issue is with the internal lockout mechanism.

 

Ideas?

[Johan Bornman]

The internal mechanism that locks out the fork is the motion control damper, a very simple plastic device that sits on top of the right fork stancion. You'll need a 24mm or 26mm socket to remove it.

 

I suggest you put your bike in a stand or similar to stabilise it. Remove the motion control damper with the socket and slowly pull it out. It is a six-inch long plastic labyrinth with an o-ring at the top and o-ring at the back. Allow the oil to completely drain from it and pull it out completely. Put it on a clean surface.  Examine it.

 

A silver steel shaft goes from top to bottom and in the middle of the device, the shaft is restrained with a spring. At the bottom of the device is a small metal valve that turns with the shaft. All of these should turn freely and return sharply when released.

 

There should be no retarted return - snap snap snap is what you're after.

 

Figure out where the retardation comes from. It can only come from a tangled spring, a restrained valve or from something constricting the steel shaft itself.

 

It'll be all obvious, don't worry if you don't follow now. Just open it, drain the oil and remove it. If you're careful you won't have to replace oil or any such thing.

 

Also, there are no things that can go boing boing when you remove it.

 

The bottom valve should turn freely with the shaft. If you hook your fingernails under it you'll notice that it can also move in line with the shaft - that's the lock over-ride. When you hit a bump, the valve's inertia opens it and the fork absorbs the bump.

 

All these things should move freely.

 

 

The only tools required is a socket and ratched. Don't do this with a shifting spanner, the soft plastic top can will round off.

 

 

 

[Johan Bornman]

If cable friction is your problem' date=' try a thicker gauge sleeve like those for the brake cables.[/quote']

 

This is crazy advice. It is not a good idea.

 

[mongoose_dude]

Thanks Johan. It sounds like you know what you're talking about. I really appreciate the advice.... Must admit - I am very interested to see what the inside of the fork looks like, so I'd like to try what you advised. However, of course I have a level of stress / hesitance because I have never done something like this. If you say that there is nothing that can explode if I open the damping side of the fork, then I'll take your word for it.

 

I do have one question, however. How is the rebound adjust bolt connected to the whole internal assembly? That bolt sits at the bottom of the shock-tube, so if I can pull out the poploc mechanism through the top of the shock, where do the poploc and the rebound adjust connect?

 

Thanks again.

 

[Johan Bornman]

Those are two separate mechanisms. The lockout at the top isn't connected to the other one at all.

The poplock is very, very, very simple.

 

 

[mongoose_dude]

Ok great... I will take out the poploc mechanism and take a look at the things you mentioned. Thanks again for the advice - I will let you know what I find.

 

[Johan Bornman]

Here are some pics of what you can expect.

 

 

This is what the poplock mechanism aka Motion Control Damper looks like in its entirety. The left side is the top where the cable mecnahism attaches.

 

 

The top. It unscrews with a 24mm socket. The top is actually aluminium, not plastic as I originally said. You can try with a shifting spanner if you don't have a 24mm socket.

 

 

Here's a centre view, showing the spring that pops the rotating shaft (visible as the silver line through the centre) back. It is a strong spring and the motion should be snap, snap snap. No sluggishness permitted.

 

 

Here's a view of the bottom valve and lockout override. It should turn freely with the silver shaft and also move freely away from the black palstic cap when lifted with a nail or knife.

[mongoose_dude]

Wow. Thanks for your efforts, Johan! That helps a lot. Will get a spanner set this afternoon and check the thing out tonight.

If one of these mechanisms should need to be replaced, what would that cost? I doubt that if I find something wrong with the thing that I would be able to fix it...

 

[Johan Bornman]

It is expensive, about R660-00. However, no need to replace. A) your fork is new and B) nothing can go wrong that needs replacement. Whatever it is, you'll be able to fix it. This thing is simple.

[Turbobok]

Remember to connect the thingamajiggie to the whatsit, and u should be fine...

[mongoose_dude]

Thanks Turbobok... exactly the type of technical advice expected from an engineer :

Johan: seems I can't get hold of a 24mm socket, and neither a shifting spanner...  So off to a hardwares store tomorrow.

[mongoose_dude]

Hi Johan

 

I took out the poploc mechanism, and it looks to me as though the spring on the shaft is not too looking too great. I don't know it is sitting in the right place, from what I see in your pictures. The different coils of the spring do not sit nicely next to each other, but are twisted sideways and the spring is not evenly thick at all places. It also looks like the spring itself is sitting too far towards the top of the metal shaft, and as if it is stretched across a greater part of the shaft than it should be.

 

I dunno whether that description makes sense... If you want, I can upload some pictures. What would your advice be?

 

Incidentally, I checked that the gate-valve at the bottom is not jammed. Furthermore, everything does snap back very nicely if i do twist the shaft. There is no sluggishness at all. It just seems that the spring is not as strong as it should be (when I compare it to my previous shock).