Campagnolo USB BB problems ?

BG2000

I've just found that my 6 month old Record chainset has a slight bit of play and feels/sounds rough when spinning it without the chain. On closer inspection, there is no corrosion of visible damage, and the bearings hadn't run bone dry. This is a 2011 Record 11 speed carbon ultra-torque chainset with USB ceramic ball bearing races. I installed it new just over 6 months ago, loads of grease etc..

What did I do wrong ? Was I supposed to have pulled the cranks out every month and applied new grease to the bearings ? I have many other bikes and certainly don't need to worry about greasing the BB every 6 months, especially not on a road bike.

So much for ceramic bearings eh ?!! (BTW USB are just ceramic ball bearings with steel cones/cups)

ugo.santalucia

I have found that steel cages with silicon nitride balls is the worst possible bearing... typically bad quality...
If it's not the nut that has come undone, then it's the bearings... replace with standard steel ones, they are actualyl better

drlodge

Any relation to this probem I wonder? http://roguemechanic.typepad.com/roguem ... -ul-1.html

BG2000

No, the nut was still fully tightened when I noticed some play. And it wasn't 'side-to-side' axial play as mentioned in that video (I would just call that float and I don't think it harms bearings). It was a slight rocking up and down, as if a part of the bearings that originally had been a perfect fit was now slightly loose of worn down.

Although the hollow carbon cranks are a work of art, and I love the Hirth joint, I am now suspicious of these silicon nitride/steel cage bearings and certainly will replace them with cheaper all steel items.

Cheers.

cycleclinic

I would also stick with steel bearings unless its a fully ceramic bearing with ceramic races but those are hideaously expensive and not much better if any than a quality steel bearing.

My power torque bearings only lasted a year ~4000. Replaced with SKF bearings I'll see how they last.

BG2000

It's a shame Chris King don't make Ultra-Torque BB bearing/cup kits

stokey1964

If you are going to use standard bearings instead of the SR usb ones, you will have to change the cups as well

The SR cups dont have a seal whereas Record or lower do


Simon

ugo.santalucia

thecycleclinic wrote:

I would also stick with steel bearings unless its a fully ceramic bearing with ceramic races but those are hideaously expensive and not much better if any than a quality steel bearing.

My power torque bearings only lasted a year ~4000. Replaced with SKF bearings I'll see how they last.

Where did you find SKF 37x25x6?

pinarellokid

it says on the campag website these ceramic bearings should be lubed with light oil not grease like steel bearings,,

not sure if grease could be the reason for the eraly failure, but it doesnt sound good to me.

cycleclinic

The campag power torque bearings that I pulled out were 7mm thick not 6mm so I feel free to replace with SKF's. They sit perfectly in the cups when installed.