Forum menu
square taper proble...
 

[Closed] square taper problems?

 ton
Posts: 24281
Full Member
Topic starter
 
[#5431637]

always used square taper bottom brackets when possible (when doing self builds), so that's is a lot of bb's over a lot of years.

built a new tourer a couple of months ago, used a un26, which I know is cheap but usually ok, it died in 6 weeks
fitted a un54 about 3 week ago. feels loose already and squeaks/creaks like buggery.

any idea's?
finger is poised over the buy button for a new xt m780 set up


 
Posted : 16/08/2013 8:46 pm
Posts: 0
Free Member
 

Had a UN26 die on me within 4 months too

Just fitted a UN55 to replace it so see how long that lasts


 
Posted : 16/08/2013 9:20 pm
 ton
Posts: 24281
Full Member
Topic starter
 

dodgy batch perhaps?


 
Posted : 16/08/2013 9:35 pm
Posts: 0
Free Member
 

I had issues with my square taper on my commuter.

The non-drive side crank arm bolt kept coming loose.

Tightened it loads until I got pi**ed off & removed it to inspect.

Turns out the 'square' part of the crank arm was far from square ๐Ÿ™

New Hollowtech 2 setup soon followed.


 
Posted : 16/08/2013 9:40 pm
Posts: 0
Free Member
 

I too used the old set up till I found out that the crank interface had stretched and no big torque would keep the bolt or arm held in place. time to get modern on it. ๐Ÿ™‚


 
Posted : 16/08/2013 9:43 pm
 ton
Posts: 24281
Full Member
Topic starter
 

modern stuff now ordered from crc.


 
Posted : 16/08/2013 9:46 pm
Posts: 0
Free Member
 

Might be - I'd put it down to maybe cross threading the NDS cup and perhaps throwing it offline / not supporting the bracket properly (ie user error in installation)

I'd be happier if it wasnt my fault tho


 
Posted : 16/08/2013 9:46 pm
Posts: 41395
Free Member
 

Creaking is a fit issue, not related to BB itself


 
Posted : 16/08/2013 10:40 pm
Posts: 5300
Full Member
 

In my experience, squeaks and creaks are often the crank arms worn and moving slightly.

What happened to the first one? Can't imagine them failing in 6 weeks. Those and cockroaches will be the only things to survive a nuclear war.


 
Posted : 16/08/2013 10:46 pm
Posts: 6126
Full Member
 

alandavidpetrie79

Same issue I had a few times. Worked out it was partly because I ride with left foot forward when coasting, which is acting against the thread direction of the bolt.

Gave up in the end, went HTII.


 
Posted : 16/08/2013 10:47 pm