?????????????????????, kind of sum's up the prob I'm having with my 04/05 Slayer frame (the chunkier 3D link version). You're prob thinking it’s just worn out but in fact it's prob done less than 800miles due to me getting into triathlon at the time.
The problem is that when I decide to put torque through the frame, especially in standing (happens in sitting too) the chain makes a snapping sound and drops a chain-ring and so I have zero confidence when negotiating obstacles or putting power down when exiting corners etc. I have taken the following steps to sort it:
1. New middle chain-ring (XT), 2 new chains ( xtr yumeya and SRAM hollow pin), rear cassette (xtr Ti 9spd). I had thought it was the xtr chain but not now as it happens with both.
2. Total rear linkage bearing and bush replacement.
3. Hope BB has seen less than 10 outings.
The only other thing I can think of are the hubs and wheels (XT hubs on 819’s), but they have just been serviced (3 rides)...there is no play at all.
However, in standing balance while pulling sustained torque through both pedals the chain stays just behind the rear suss pivot appear to be flexing….quite a lot. Could the alloy have become weakened over time?
Really odd, I just can’t seem to suss (ho ho) it out? The bike just feels like it’s lost all rigidity?
Any ideas?
its not the frame, all bikes bend,
I sort of thought so, but I'm grabbing at straws tbh? I guess it looks so thin and skinny next to the new machines... 😛
Forgive me for bleating on about what is, possibly, the most basic of issues.
After checking all possible causes, including the chain ring nuts, I found nothing. So, after googling it would appear that the most likely cause is drive train.
So, convinced I'd find nothing I looked at the rear cassette. Bearing in mind it's seen no more than 10 rides (20-25mile ave, xtr ti)and stone me if it's looking worn?? Ironically, it's the smaller alloy cogs as opposed to the Ti larger ones than are used the most.
That seem a utter pants, longevity wise? So, XT or Sram replacement?
Drive train is xt.
Cheers.
Have you checked all the bearings and pivots are done up to the correct torque and there's no cracks in the frame?
Chain line maybe but I would go with free hub, thou you said the wheels have been serviced, you can't do much with the freehub.
If I was you I blag another rear wheel, swap cassette over and see if it happens again.
Sounds like you donethe right thing replacing, middle ring, chain and cassette.
The only other thing is maybe a bent tooth or twisted link, but I think thats unlikely as they new-ish.
Love Tubs,
Interesting point you make about the cassette.
The steel sprockets will show burring as wear, but the titanium sprockets just wear away without any burrs. XTR has only Ti or steel sprockets, no aluminium alloy ones (see KCNC on this forum).
Hard to know when they are shot unless they slip under load, and that is unusual for sizes larger than 20T (Sheldon Brown's comments).
Still, 250 miles is not enough to even think of it as being worn out unless they were all in very abrasive slurry!
Looking forward to your denuement.
When my bike was doing something similar it was due to 3 of 4 pawl springs in the pro ii hub having fractured.
Oh shoot, I hadn't thought of that...I really am quite pants at this mtb maintenance thing. You know, it could be related to that because yes there's signs of wear of the cassette but surely the life-span should exceed 500 to 800 ish miles?
The hubs are only XT and are now in their 6th year...however I have had them serviced, surely broken pawls would be picked up by the techie?
It seems everything needs replacing all atm 😥
Just wish I could bung a good wheel in to check before spending more cash one bits I might/might not need.
Frustrating.
Retrospectively;
Since the only thing remaining was to replace the cassette...I replaced the cassette...and guess what happened? Miles and miles of silky smooth - crispy quick gear changing sex.
I'll never buy a Ti cassette again.
I am rubbish btw.
QED
So, do you think the ti rings were flexing under load, or were the teeth badly shaped?