How to check for wear in the pivots and shock mountings?

[steve_sordy]

Focus Jam2 carbon framed 29er, 2165 miles on the clock. I have begun to notice a small "clunk" feeling when going off anything much over a foot high and sometime less if going faster. It's at the rear and I wondered if it was wear in the shock mounting bolts or the pivots. The suspension is a linkage controlled single pivot. The shock mounting bolts were replaced at 740m, and at 1431m the pivot bearings at the top of the rear triangle were replaced by the LBS when it was in for something else. Other pivots are untouched since new.

I let the air out of the shock to release the tension in the system and flexed the bike frame sideways, lifted the bike up with my foot on the pedal and pushed it down. I could neither feel nor see any detectable movement. Am I doing this the right way?

If it's not them, what else could it be? The rear axle is secured at the correct torque and secured with Loctite blue.

 

[Billybopsbasher]

Leave the shock pumped up.
Put your foot on the rear wheel as best you can. Then lift/put down a few times the main part of the frame with one hand whilst feeling both top and bottom shock mounts for any movement. Do the same again with the main pivot above the bb and then as best you can with the pivot on the seat tube underneath the fold linkage... Those are the main culprits on mine. Sounds like the shock eyelet bushings.

 

[Telemarker]

I often lift the rear wheel off bike off ground, with one hand holding at base of dropper post and drop the wheel on ground still with hand holding bike, and you can usually feel a jolt if something loose.
And then To identify which bearings/pivot might be worn keep both wheels of bike on ground, and with hand holding bike at base of dropper post, I push down and pull up on frames. And with other hand feel shock mounts And pivots as bike is moving.

 

[Telemarker]

I’ve got a lot of rattling going on , my Sam2, when riding down rough trails, And did the checks above Andy can’t find any pivots or joints at fault, I think it’s coming from motor, internally.
Cranks have no play, and BB play doesn’t seem worse than it was new

 

[steve_sordy]

I’ve got a lot of rattling going on , my Sam2, when riding down rough trails, And did the checks above Andy can’t find any pivots or joints at fault, I think it’s coming from motor, internally.
Cranks have no play, and BB play doesn’t seem worse than it was new

I hope it isn't the motor, I already checked that the motor mounting bolts are OK. The BB is solid and smooth. Now I've had more time to think about it, I will also check the dropper. The saddle can easily be twisted from side to side, which of course I can't detect with my arse. The post has no up/down movement at all, other than that desired. I'll pop into the garage, undo all the chains and cables, and check as recommended by @Billybopsbasher and @Telemarker
Thanks all.

 

[steve_sordy]

Hmmm. I just did the checks advised and found nothing, not even a hint of any movement. Which is good of course.
I then checked the pedals. I have DMR Vaults and the bearings have been replaced many times, most recently less than 600 miles ago. While I was heaving on the pedals I detected a bit of movement. There was some from the pedals on both sides, but not something I would fuss about. And there is also a very small amount on the BB. Now I've found the BB movement it will nag at me. It's not the sort of movement that would have had me worried on my previous analogue bikes, but I would have made sure that I had a new Hollowtech II BB in stock, just in case. I very much doubt that the BB is going to get bad enough before my warranty runs out early next year. (If the BB is the culprit).

I will regrease the pedals before I go out tomorrow. It doesn't take long and it can't do any harm.

 

[deksawyer]

I had a loud intermittent click sort of a sound and was convinced it was the motor. Turns out it was a rear wheel bearing.

 

[iXi]

I had a loud crack when going off any sort of drop or over a small jump. I checked all the Pivot bearings and although all but the 4 were smooth to spin and the four that weren't were still fairly smooth they felt a little bit notchy.

Bike shop said bearings showed no movement so I should be sweet but I got them to replace them anyway and sure enough the crack is gone.

 

[steve_sordy]

I took the bike to the LBS for a 2nd opinion. He could find nothing wrong with any of the pivots, upper & lower shock mount, spoke tension, rear hub, motor mounting bolts, rear axle, or the dropper post. He discovered that when the cranks are vertical there is some slight movement in the BB but at no other angle. I wasn't bothered by the BB play as it was minimal. But I guess it means that when it does fail it will be well outside the warranty period. I'll keep my eye on it and consider claiming before the end of the year. But from @myapes experience, they have to be pretty bad to be accepted; his was rattling.

What the LBS did find was that the shock rebound was acting up!! The rebound was super slow! He wound it faster by 7 clicks or so, then back to the same place; the shock rebound was faster! When I went out again I could not make the noise happen again, so what I reckon is that the the shock had been packing down and I was bottoming it. ?
When I got home I checked, and the shock has done 1095 miles since its last service, so it needs some TLC anyway. I'll do that next.