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View Full Version : Why is my BB unscrewing?



xanda2260
05-24-2012, 03:21 PM
Hey guys, need some help.

I'm about 95% done with my electric warrior, but I'm having an issue with the bottom bracket.
I'll admit my bike knowledge has come entirely from this build, so I know very little.

When I'm using the trike, pedalling along etc. The BB unscrews itself. When it has screwed out enough for the axle to wiggle back and forth, I tighten it up again. Only takes about 30mins of riding to unscrew it.

I thought the lock ring was to stop this happening? What am I doing wrong?

Any advice gratefully recieved.

Cheers guys

Alex

David_s
05-24-2012, 05:29 PM
Did you put it on backwards? Isn't one side reverse threaded to prevent this from happening? Pic would help.

darnthedog
05-24-2012, 06:39 PM
I'd check out the DIY tutorial Bottom Bracket bearings. The right side should tighten in the clockwise direction were as the left side should turn Counter clockwise. The Lock nut is to maintain space for the bearing and should not come loose.

wonderer
11-02-2012, 05:15 PM
I had bought a new sun recumbant (2 wheel) & I had the same issue. Took it in to the dealer & he really torqued it down hard, still came lose.

The treads had worn & were slightly egg-shaped, I saw.

Took the bike back in and he had to install a deeper threaded bearing race, that took care of the issue.

wonderer

Radical Brad
11-02-2012, 08:08 PM
You could always try a cartridge bb.

Brad

John Lewis
11-04-2012, 02:40 AM
It does sound like the BB may be back to front.

All is not list if thats the case. Just turn it arpound and redo the deraileur tube.

I think some blue loctite would probably do the trick otherwise if you don't want to cut it about.

John

PeterT
11-04-2012, 05:26 AM
unless you have actually found an ancient italian BB, which was made that way, your BB is reversed.
Two options: rebuild the trike back from the BB, in the reverse direction or cut off the BB and change it 180 degrees :)


PeterT

John Lewis
11-05-2012, 09:09 AM
unless you have actually found an ancient italian BB, which was made that way, your BB is reversed.
Two options: rebuild the trike back from the BB, in the reverse direction or cut off the BB and change it 180 degrees :)


PeterT

Trust Peter to think out of the box and come up with the definitive answer.:jester::jester:

John