Dura Ace 7800 bottom bracket wear question

Have you had the BB serviced? You can lift the seals and add more grease.

What about the condition of your hubs and chain?

The best way to check the performance of your BB without disassembling it is to take the chain off the chainring and spin the crank by hand, smooth and quiet (good), rough and noisy (bad).

I have a friend who only had approx. 3500 miles on his BB and had to replace it. At our shop the Cat II riders seem to go thru a DA BB every 3000 to 4000 miles during the season. But that is with really long hard riding and racing with consistent watts in the 285+ range. Could this be a trend? Possibly. I do know that there are other companies making alternatives to DA OEM BB's that seem to take a whole lot more abuse. So your concerns are definitely warranted.

melville said:

I have put about 8500 mi. on my bike and am wondering what the signs of spent bottom bracket bearings are. I know that they're gone if they have lateral play (like hubs), but I'm wondering if there are other symptoms. Specifically, can they bind and cause friction or resistance? I've noticed increased effort (watts) for the same output (m/hr) on the same roads I ride all the time. And if I ride one of my other bikes, it seems more fluid. The LBS said they seemed fine, "smooth," but I still wonder. Anyone?

Thanks for all the response. As I say, I just got it back from LBS, the chain is new, the hubs just adjusted. So I'll try what you guys have mentioned. Worst case, I'll buy a new bb and if there's no difference, I'll take it off and put it on the shelf till this one's gone.

You're not actually changing the BB but the worn out BB cup/bearings. FSA came out with ceramic ones code CR3798 (red cups)... excellent altho pricey. They look similar to DA but don't know if compatible ... the LBS should know.