Bike Forums - Irregular BB?

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I have an '09 Madone project 1 that my team got a good deal on. After about 500 miles or so I noticed some noise coming from the bottom bracket and after looking closer I realized the crank arms were slightly loose. After taking it to the shop and letting the mechanic take a look, he decided the bottom bracket was slightly ovalized. This would be a factory defect and the frame would have to be replaced. A couple days later, however, the Trek sales rep. was in the shop and he said that there was "a small number" of Madones made with a slightly larger bb shell than normal and that Trek makes oversized bearings to fit it. Has anyone heard of this?

My thought is, the frames were a mistake and they made the bearings after realizing the mistake because it's cheaper than replacing all the frames. In which case, why should I trust that the replacement bearings will fit properly? Seems strange and I can't find info anywhere about this issue. Aside from this bit of bad luck, the bike is great.

OS bearings to fit out of tolerance BB shells? Sounds like a load of sh1t to me. I'd request a new frame.

Quote:

Originally Posted by fatallightning (Post 8914577)

OS bearings to fit out of tolerance BB shells? Sounds like a load of sh1t to me. I'd request a new frame.

+1

Especially since down the line it is going to be impossible to find these "special" bearings.

I just got an oversize bearing put into my '09 Madone BB, sure would like to know if this turned out to be a 'defective' frame.
Did you pursue this with Trek?

no, not racing, after 10,000 miles i noticed some play in the BB, the rebuild kit needed an oversize bearing on the non drive side, perhaps a mfg defect as stated by "cmberes" (OP). Wondering if Trek has admitted to faulty manufacturing.

Also bear in mind that the BB itself may be substandard if it was manufactured in the Shimano Singapore factory.

I live near Singapore, and local bike shops drawers are replete with their prematurely junked BBs.

It has come to the point, if you want to be sure of a decent Shimano BB, you have to get somebody to buy it IN Japan.

It is a long standing problem with their quality control.