I had a new BB (105 Hollowtech II) towards the end of June, and last ride out I got it into my head that the bearings were shot- rumbling noise and seemed to be a bit too much resistance/drag in the BB. (I don't really know how I'd decided that any resistance would be in the BB rather than the rest of the drivetrain and/or my legs, but that's what I reckoned!)
Anyway, last night I had a look and spun the cranks with the chain off- no noise, but it did seem a bit sluggish and it would stop spinning very quickly when I let off pushing it. I did the same with my commuter and the cranks spun much more easily and for longer.
So I guess the question is- can they really have got worse over a few months, or were they always this way and it's all in my head? I did have one pretty wet ride a few weeks ago but other than that it's all been dry, and it's probably only done a few hundred miles since new.
And on another note, are replacements pretty much interchangable- would, say, a Hope BB work OK with my existing cranks?
