SRAM DUB bottom bracket failure

[figbat]

A few weeks ago I noticed that the cranks didn't spin easily on my newest MTB. However after a cursory whizzing around of the cranks with the chain off it all freed up and was OK again.

Today I went to it again and once again very stiff cranks. No amount of whizzing was freeing them up so I had the cranks off and discovered the NDS bearing was seized solid - the crank spindle was turning inside the bearing. As luck (or foresight) would have it I had a spare BB so I put that in with plenty of greases and all is well again.

It's a SRAM DUB setup, a new-to-me standard and I'm not sure I like it. The bike was a used demonstrator but came to me looking unridden. However I found a couple of assembly issues (derailleur hanger not tight/no thread lock, gouge mark on the fork yoke) and I'm thinking that this BB had been hastily assembled with little or no grease (none apparent on disassembly).

I'll admit I am not a great bike maintainer and it'll often sit from one week to the next without being cleaned after a ride. However this is exactly how other bikes I have are used and not a one has ever suffered BB issues like this. I've only done 300 miles on the bike (including biblical rain, but nothing other bikes haven't also suffered).

Bad luck? Bad assembly? Bad part? Bad maintenance? Is SRAM DUB a good or bad thing? I'm not a fan so far what with this and the stupid little preload collar.

 

[Cycleops]

Is this similar to Shimano Hollowtech? Two piece crank? Could you post a pic?
I have two bikes with this on with no problems.
Some bemoan the unpopularity of the old square taper BB for these modern alternatives.
Sounds like you were unlucky and got a duff one.

 

[Jenkins]

<Snip>
The bike was a used demonstrator but came to me looking unridden. However I found a couple of assembly issues (derailleur hanger not tight/no thread lock, gouge mark on the fork yoke) and I'm thinking that this BB had been hastily assembled with little or no grease (none apparent on disassembly).

I'll admit I am not a great bike maintainer and it'll often sit from one week to the next without being cleaned after a ride. However this is exactly how other bikes I have are used and not a one has ever suffered BB issues like this. I've only done 300 miles on the bike (including biblical rain, but nothing other bikes haven't also suffered).

Bad luck? Bad assembly? Bad part? Bad maintenance? Is SRAM DUB a good or bad thing? I'm not a fan so far what with this and the stupid little preload collar.

I think this may be the main problem - as a demonstrator it's probably been subject to harder use and less maintenance than if it was owned and ridden by an individual.

I've got SRAM DUB on my Bootzipper and it's done around 2500 miles with no maintenance, but ridden in all conditions and used mostly as a fat slick tyred hybrid in all weathers or snow bike on knobblies and only light off road use.

 

[figbat]

Is this similar to Shimano Hollowtech? Two piece crank? Could you post a pic?
I have two bikes with this on with no problems.
Some bemoan the unpopularity of the old square taper BB for these modern alternatives.
Sounds like you were unlucky and got a duff one.

Yes, very similar to Hollowtech. DUB BBs are available for various shell types , mine is an English threaded one with semi-external bearings.

The seized bearing is absolutely solid, I can’t move it at all.

 

[Ajax Bay]

Enjoy this (DUB):

View: https://www.youtube.com/watch?v=1VeKVSbhIoc

 

[figbat]

I'm not a fan so far what with this and the stupid little preload collar.

Hambini and I are in agreement then, although my comments use fewer expletives (whilst doing the job I would have give him a close run).

 

[fossyant]

DUB is no better than GXP for this, i.e. letting in water. I've changed to a Praxis Works GXP.