hey ken, you could just have a loose BB cup. i'm assuming the pistas have a shimano type cartridge BB, so all you have to do is remove the crank arm and tighten the cup down, its a pretty easy fix. try the non-drive side first, because in my experience thats the one that'll loosen first. oftentimes, its a good idea to check the tightness after a couple of hundred miles, especially given that its a new bike and it'll take that long for things to settle into place. also, the cups should be tightened to around 300 to 360 inch pounds. as far as replacing the BB, it seems crazy you would have to at this point. but, assuming what i have about the pista's BB, you should be able to use a shimano un 52 or 72 with the same spindle length and it'll last for a long time. or you could go really crazy and get a phil wood or something that'll last even longer and give you the option of dialing in chainline a few mm or so.