Really bad creaking SB-66

[milko]

I am a bit stumped by this.

I've had the SB-66a since November 2011. Recently it started creaking a lot, and so I got the shock serviced (and PUSH tuned, and new bushings at each end), and all the frame bearings replaced by a local Yeti dealer. This cured it! More accurately, the frame bearings cured it, I did the shock first and it made no difference. 

So! About four rides later, the creaking is back. WTF? I just finished stripping the frame right down, cleaning and greasing everything and checking it's all torqued up the way it should be. And it's made no difference whatsoever.

Here is a video of it just now, being made to creak. (You can also hear the slightly squeaky sound of the shock which I gather is normal)



So, any ideas what could be causing that? Unlike just before I had them all replaced, the bearings all look in good order. The only thing I could say looked a bit off was that one side of the eccentric is showing some signs of wear:



The pivot axle looks slightly worn in the corresponding area too. Could that be enough to cause it/is it enough to be a worry anyway? Having just done the shock and bearings I'm not gonna be particularly impressed if I have to do this as well, looks like another £150 if so to replace. And then it would beg the question of why this wasn't creaking for those four rides after the bearings were replaced?

Oh, and it makes this noise if I'm standing on the pedals, not actually turning them. I'm as certain as I can be that the seat, post, cranks and BB are not involved in the problem.

As I say, I'm stumped. And I don't mind admitting, more than a little frustrated. Would very much welcome any helpful advice!

[milko]

I was back to stripping the frame right down tonight and just trying again. And I got it! I think it was the lower dogbone pivot, the one that doesn't have a separate cap on the non-drive side. I suspect there wasn't enough grease between the bearings and the inner race extenders. There is now, and all is well again.

[rocketmagnet]

Yeah that's the sound of a pin binding IMO... Normally this means a bearing is shot and not rotating so the pin rotates instead.. binding and cracking as it does... enough grease can quieten it down (allow the pin to spin freely but it's not a fix just covering up the symptom and will come back).

However you've clearly "fingered" your bearings and they are fine so rules this out?
With good bearings and the same binding occurring I would have questioned over torque of the pins on the bearings.
IIRC its 10.5Nm and if you can be bothered your supposed to not torque to the final torque in one go but in a couple of stages.. e.g 5Nm then 9Nm then finally 10.5Nm or something similar. Was told this by a fitter but usually I can't be arsed
and go right to final torque but I'm careful and smooth.. once I get there I stop immediately and don't "retest the torque" as you should not as your actually over torqueing doing this..
Sorry if you already know all this but worth saying again imo.

not thought this one through but possibly the pinch bolts could produce this effect also..?