Last year in July, the bottom bracket on my Xstream started getting noisy and loose. It had about 1000 miles on it. The bike shop replaced the bearings, said they didn't know what would have caused the failure. At the time I chalked it up to bad luck - maybe they were bad from the factory, maybe they were damaged during install. Now I'm pretty sure there must be a cause of some kind, because they squeak badly again, especially under load. The bike only has 2380 miles on it, so there's something going on. Are these things sealed cartridge bearings, or do they need to be lubed and adjusted periodically? If it isn't poor maintenance and it isn't the bearings, there must be something slightly out of kilter with the housing. Would a local bike shop like Colonels be able to face the ends of the bottom bracket and true up the bores, or is it more involved than that? Please let the opinions flow, I'm kinda at a loss here.

I guess I'm lucky on mine but I've never had a problem with any bike I've owned.  Anyway I have apx. 15 grand on my Xstream and I have replaced the chain, cassette and rings. The bottom bracket is still smooth.

The Bike Whisperer (aka JayG) told me to check my chain ring bolts...two of them were a little bit loose, and that was the source of the squeaking. They weren't loose loose, they just weren't super tight. So let that be a reminder to my fellow engineers....sometimes problems are simple, so don't be so quick to look for complicated answers!
 
Thanks Jay, I owe you a root beer float!  

Quote from Tiger_Mike on Jul 30^th, 2013, 9:51pm:

 
When they get a little more loose and all but one fall out from rough chip seal when you are Meunster, it will sound like someone hitting a fence post with a sledge hammer.  And your small chaingring will look like it is bent while it flops around.   Dont' ask me how I know.