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I have an old pair of XT HTII cranks and the non-driveside constantly wobbles.
Preloaded the cap by hand, tighten the bolts to correct torque, withina few miles its all over the place. This has lead me to over-tightening the preload cap and killing BBs in the past. Have I worn out the splined interface? Anyone else had this happen?
knackered splines would be my guess. You can try over tightening the pinch bolts and using loads of threadlock on them and the splines. I had this with a Race Face crank. It held for a bit but always loosened off in the end (and usually at a bad time).
Inspect the splines.
Had mine start wobbling the other weekend, turned out the wrong (too wide) press-fit BB had been fitted - leading to not enough purchase on splines and eventual self-destruction mid-ride.
I've had this on two sets of deores HTII's. Tried thread lock and tightening them up super tight but they kept wobbling and falling off. They were just knackered after years of abuse. In the end I replaced them and haven't had a problem since, but I don't ride my bike as much as I used to so I guess they'll last a bit longer now!!
Just like old taper cranks, ride them loose once and they are for the bin.
turned out the wrong (too wide) press-fit BB had been fitted
I've had that before from a generic Taiwanese BB. (GUB I think). Fiotted to a bike with a 73mm shell, only used one spacer, but the crank simply wouldn't go on.
Just like old taper cranks, ride them loose once and they are for the bin.
Makes sense. Woot! Upgrade time!
Surely if the BB is too wide the little plastic spacer between the bolts won't pop into the hole in the axle?
It is my experiance that the correct torque for them torque bolts is laughably low and results in cranks falling off.....
That is doing incremental tightening as is correct for pinch bolts.
It's 'cause you're a ham-fisted oaf, that's why.
You could pack it out with a load of loctite to try and prevent the wobble reappearing or a metal (and therefore stiffer) preload cap might help resist the wobbling.
BTW I wasn't suggesting your BB is too wide as well, just explaining how mine worked loose.
Really unusual having trouble with Shimano cranks, the securing system is great and I've not had a loose crank for about six years.
It's 'cause you're a ham-fisted oaf, that's why.
I *may* have stripped a thread in your stem Jon too...
Problem isn't helped that these cranks have been on and off more times than I care to think of, and as pointed out, once loose, they only get looser which wasn't helped by the ill-fitting BB.
I *may* have stripped a thread in your stem Jon too...
LOL I did say they were fit for testing only. Put them in the bin* when you're done!
*pile to go to the tip