Cracking sound when installing a press-fit BB

[Pierre]

Hi gang,
I was in the middle of installing my Shimano BB92 on my Look 675 frame yesterday when about half way through I heard a short plastic sounding crack(my guess is plastic, not carbon). The sound was not loud but it was a cracking sound for sure. At the time, the bearings were going in nice and straight and the cracking did not continue when I continued to slowly press the bearings in. The frame in question is carbon but it does have an aluminum sleeve in the bb. Has anyone had this happen? The bearings, once installed roll smoothly and all seems good...

[pavel]

Was there also by chance a plastic sleeve connecting BB halves?

[Pierre]

yes there was...in fact, my first guess was that the sleeve cracked...are you thinking same?

[pavel]

yes. If you havent installed the crank yet, can you stick a finger in there and feel around for a crack?

[Pierre]

I've put the crank on but no big deal to slide back off. If it IS cracked (the plastic cylinder, that is) I'm thinking it's not the end of the world...am I thinking wrong?

[kittytrail]

worst thing that can happen is for water to insidiously seep in the BB and the frame starts to rust and crust! ;)


:D

[Dead Man]

Those sleeves are usually a pretty soft plastic that seems like it wouldn't tend to just crack/split like that.. But yea, jam your fingy up in there and see if it's split.

If you never ride in the rain, it's probably NBD. If you live where I live... and you want your BB to last longer than a couple months... you're gonna want to replace the sleeve. Assuming it's cracked.

[11.4]

The cups themselves are plastic too on that unit? The plastic sleeve can crack at the ends, or longitudinally, or in just snap off a piece. The only way to know it wasn't damaged is to remove it and inspect. And if there's any damage to the cup, or if it prevents the cup from seating perfectly, it'll be up for replacement soon. I'd do it right.

[Fatty]

Is that not a PF30 frame?
BB92 bottom bracket is compatible?

[Chief]

yes. If you havent installed the crank yet, can you stick a finger in there and feel around for a crack?

Be sure to use a rubber glove and some lubricant. :beer:

[SoCalSteve]

Be sure to use a rubber glove and some lubricant. :beer:

Post of the day!!!

[austex]

Be sure to use a rubber glove and some lubricant. :beer:

...Licensed Bicycle Proctologist. :beer: