Spontaneously loosening cassette lockrings and crank bolts

AllanT

I keep getting a problem with my Raceface turbine ISIS Cranks & bottom Bracket (both brand new). For some reason the crankbolts loosen occasionally, leading to the crank working loose. It's happened once on the left hand crank (leading to the bolt getting lost, had to replace that), and last night on the right hand cranks (managed to tighten it up on the road, then properly tightened it at home with the right size allen key.

On top of that, the cassette lockring loosens off occasionally (did so last night, tightened that up as well),this is on a pair of brand new Mavic Crossrides, with an XT cassette.

When I'm tightening off the bolts I'm doing it by hand, but tightening up as much as I physically can

Any suggestions for what might be causing the problem, should I be considering using a torque wrench to tighten them up?

nicklouse

torque them to the required ammount. may be a thread lock on them first.

cassette ring not tight enough.

sounds like you need some spinach.

AllanT

nicklouse wrote:

torque them to the required ammount. may be a thread lock on them first.

cassette ring not tight enough.

sounds like you need some spinach.

I do get concerned sometimes that I might be at risk of overtightening them, so I may back off before they're really tight enough? That said when tightening, I try to use my whole bodyweight, rather than just my armstrength?

nicklouse

the only problem now is that as they have come lose once you could have damaged the splines.

re tightening i dont use body weight but pull the allen key (long) towards the crank arm. (both are about the same length.

royboy11

For crank bolts there will be a manufacturer spec for what to torque them to. Probably around 40 ft-lbs.

And i agree it sounds like the cassette lockring wasn't tight enough. The spinach should help!

lachoman

Just tighten it up till it snaps and back it off half a turn. But seriously, you can tighten stuff up much much tighter than spcified torques and be safe that it wont snap, especially with steel threads like a BB.

skyliner

Crossrides have a spacer on the freehub, to help seat the spoke protector. If this is missing, it may feel like the cassette is loose, even though the lockring is tightened to 40Nm, as it should be.
If it is, in fact loose, try more spinach. (as suggested)

AndyGates

Do not fear overtightening. Fear is the mind-killer. Fear is the little-death that leads to spontaneous loosening. Face your fear. Let it flow over you and through you...

and eat more spinach