Bicycle Mechanics - Crankset and bearings thrashed

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View Full Version : Crankset and bearings thrashed


lesiz
11-09-08, 12:43 PM
Bad news for me, the bearings in my bottom bracket went bad and scored the shaft of the crankset, so it looks like I'm in for some expensive repair, unless the bike shop that I got it from will cover it under warranty. I haven't approached them yet.

The equipment specifics are Dura-Ace 7803 crankset and Boca Dura Ace full ceramic bearings.

I got this bike in April '08 and in that 30 weeks have ridden almost every weekend, on the average 100 miles with 4,000 feet of ascent. This problem became evident on my last ride, in which I encountered rain, so I suspect dirt got splashed up onto the crankset and somehow found its way into the bearings.

Am I right in thinking that even with that considerable usage, that this premature wear? Would improper installation by the bike shop be a likely cause?

I haven't done any maintenance on the bearings in that time, like taking them out and cleaning & lubing them. Was that a mistake?

Ceramic bearings are nice for reducing friction, but are they a lot less durable than steel?


operator
11-09-08, 12:53 PM
The problem is the ceramic bearings. They ARE less durable. For meaningless performance increase on non-world record setting events.

mcoomer
11-10-08, 12:28 PM
If the bike is April '08 new and we're talking about original equipment purchased from and assembled by a shop you should be covered under warranty. Also, if you are having a bearing failure I doubt it was due to one ride in the rain. More likely that something else is at play here.

As for durability, I can only go by what I hear and I think that it's universally accepted that ceramic bearings have are harder and have a longer service life than steel. Obviously, a bad set of bearings is a bad set whether they're steel or ceramic.

Take your problems to the shop and ask for warranty repair.

Mike


lesiz
11-10-08, 09:06 PM
Thanks for the info peoples. I'm working with the bike shop and it looks like this will be covered under warranty.
During the downtime I will be indulging in nostalgia, riding on my vintage Trek 1100 -- with steel bearings.