BB seizes overnight

afcbian

I noticed that my cranks/BB seize when left overnight. This has not happened before.
They spin very freely normally but when left overnight they seize. You can free them up easily with slight pressure and they spin freely again until left overnight again.
I also noticed there is very slight movement on the BB.
I am planning to take the cranks off later and remove the BB and if required will replace the BB.
Just wondered if anyone else has experienced this ?
The BB is Hollowtech 2 and the cranks M760 XT

nicklouse

if the seize then they can not turn.

do you mean that they are stiffer to move in the morning?

could be contaminated grease in the bearings.

HT2 have never spun that freely.

afcbian

Yes stiffer the next time I move them

chunkyboy

@afcbian. I recently had a similar problem. After riding my bike, cleaning it, leaving it over night/couple of nights i found my drive train was a bit on the stiff side the next time i used it. After a few turns it felt free/normal again. But mine turned out to be a clogged up jockey wheel on the rear mech, not the BB. So, if you've not done it already, check all the drive train as it may be something similar to the problem i had.

neninja

Unhook the chain from the crank in a morning and see if you can still feel any resistance or grinding when you turn it.

If you can then I guess it's a new BB or BB bearing required

RIKO

I had a similar issue on a set of HT2 cranks. It got progressively worse with a 'notchy' feeling to it. It turned out when I stripped it that the non drive side was badly contaminated and had seized. The other side was ok, despite freeing it up with oil and grease it never really cured it and had to be replaced.

afcbian

It doesn't currently have a chain on it as I totalled the rear hanger, chain and deraileur last week and am awaiting new parts
I will take the Crank off and try to clean any contaminated gunk etc out and if no better will simply change the BB
Ahh the joys of mudplugging
Thanks as always for the advice

nicklouse

when you rotate the crank what can you feel?

also who fitted the BB?

what is the bike....