Classic & Vintage - HELP! BB/crank just locked up?!?!

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View Full Version : HELP! BB/crank just locked up?!?!

Drummerboy1975
01-03-12, 08:17 AM
My buddy has 1988 Trek 1000. The other day we were out on a ride and all of a sudden it was like someone applied both brakes. He could barley pedel. The crank will not turn by hand but will turn if forced with your feet. What might have caused this? We haven't torn into it yet but I'm thinking its the bearings in the BB?

Bikegeek1968
01-03-12, 09:03 AM
It probably has caged bearings, and a piece of the cage cracked off and wedged itself between the balls and the races. The cages are usually softer metal, so hopefully the races have not been messed up. I used to see this all the time when I was a shop monkey back in the 80's
bigbossman
01-03-12, 10:18 AM
Or maybe a cup has backed out and tightened up against the back of the crank arm.

illwafer
01-03-12, 06:28 PM
my guess is the freewheel is done.

remove the chain and see.
randyjawa
01-03-12, 06:37 PM
Cracked ball or busted cage, would be my first thoughts, if it is indeed the bottom bracket. I have my doubts that the freewheel would be the culprit, but dropping the chain off the the crank rings would be the first place to start your trouble shooting efforts.
acoffin
01-03-12, 08:08 PM
my guess is the freewheel is done.

remove the chain and see.

The freewheel would have probably thrown the chain. Most likely is bearings or cage.
John E
01-03-12, 09:49 PM
If the lockring is loose, epicyclic action will cause the adjustable cup to self-tighten.
Drummerboy1975
01-04-12, 05:51 AM
He txed me a photo last night at home. It looks as though the cage in the non-drive side has backed out. I'll see for myself today.
Grand Bois
01-04-12, 07:41 AM
He txed me a photo last night at home. It looks as though the cage in the non-drive side has backed out. I'll see for myself today.

I'm trying to make sense of that.
Drummerboy1975
01-04-12, 08:51 AM
Ok, here's the deal. His non-drive side bearing cup backed out and is cracked as well.
thenomad
01-04-12, 09:22 AM
time to get a new BB, and check the BB shell on the frame to see if its cracked.
bigbossman
01-04-12, 10:30 AM
Or maybe a cup has backed out and tightened up against the back of the crank arm.


Ok, here's the deal. His non-drive side bearing cup backed out and is cracked as well.


What do I win?





:D
Drummerboy1975
01-04-12, 10:33 AM
What do I win?




:D

A free life time supply of condements from Burger King. Just tell them I sent you.
Epicus07
01-04-12, 12:54 PM
Lol
haddawad
01-06-12, 03:28 PM
You can pack the bearing of the new BB with the mayo :)