For a while now I have got a knocking noise coming from the rear suspension on my 08 Anthem. All the pivot bearings seem fine with no play in them. I've removed the shock(RP2) and the reducers and bushings look ok can't feel any play even when the shock is fitted and the saddle is lifted there doesn't appear to be any noise or play from the bushings.

The mounting bolt felt a bit loose when inserted into the reducer of the front mount and there is a little bit of play there, spoke to the guys at mojo and they said that a bit of play there is to be expected and should be fine once the bolt is tightened in the frame.

The holes in the frame mounts look ok to me, again with a very small ammount of play when the bolt is put through them.

When the shock is fitted and the front bolt left slightly loose there is some slight play which goes when tightened, but when you sit on the saddle and compress(bounce) the shock the knocking returns, only with compression, not when the shock is extending.

I've tried letting some air out so I could compress the saddle with my hand whilst trying to locate the noise but still can't seem to pinpoint it.

Also the noise is there even when the propedel is on, sounds slightly different though!

The shock is about due for a service so I was wondering if that would solve the problem as mojo would also install new bushings and mounts, but don't really have the cash for that at the minute and I would be gutted if it came back and the noise was still there as it was something else making the noise.

It's starting to get annoying now to the point where last night I almost launched the bike out of tha garage 😡 as I'd had enough of bouncing around on the bloody thing.

Any ideas??

is the saddle loose on the rails?

see: http://www.singletrackworld.com/forum/topic/fox-rp2-with-pro-pedal-clicking-issues

remove the shock and cycle the suspension through it's full range of movement. Any noisey or rough feeling bits of travel?

And second the saddle check, try compressing using the top tube. My SDG Bel air clicks like a very clicky thing.

Stu.

how much seat post have you in the frame, is it moving here too?

BUshings at the top of the shock? Mine started to knock but it took them to get pretty bad vefore i tracked it down.

Either the shock bushing, which I have had to replace a couple of times on my Blur, or just stiction from the shock in which case it probably needs servicing

I serviced my RP3 a while ago. Took 20mins and very easy – not worth paying £90 for someone else to do it.

You can't really tell the condition of shock bushings by looking at them. My first thought was shock bushings as this is 99.9% of the time responsible for suspension noise.

Probably time for a service.

Sponging-Machine:
The bit you've done is the air can service. This is not the same as what MOJO or TF do. They do this, but also replace the bushings, mounting hardware, the internal seals and the damper oil. This is something you cannot do yourself without a nitrogen charging kit (around £500) and a load of mechanical aptitude. If any nitrogen is left in that shock as you take it apart the piston will shoot off with enough force to go through a ceiling or a garage door. It is important to service the air can regularly, but every now and again you do need to pay for a full service or you will write the shock off early.

Try lifting the bike by the back of the saddle and dropping it a few inches to the ground, if you feel a knock like this when the suspension linkage isn't moving it is likely to be the DU bush on the shock. They only need to be worn a little bit to make a difference. Not too expensive to replace but makes a big difference.

I serviced my RP3 a while ago. Took 20mins and very easy – not worth paying £90 for someone else to do it.

how did you re-pressurize the damper? 🙂

I serviced my RP3 a while ago. Took 20mins and very easy – not worth paying £90 for someone else to do it.

Err no you didn't.
You did an air can service.
A full service includes the damper in the middle, which I very much doubt you can do, and refill the damper to 250psi with nitrogen or whatever is in there! 🙂

Thanks to all, thought it was the saddle at first but eventually managed to rule that out, I'll have another look over it tonight but I should send it off to mojo for a full service as I'll bet it's well over due, at least if that doesn't cure it then I'll know the shock and mounts are ok 🙄