I just robbed the OEM ISIS BB from my soon-to-be-gone Pista to temporarily outfit my new baby (pics forthcoming). While transplanting it, I noticed that the spindle, while it turned without apparent grittiness or noise, had a quite considerable amount of resistance. The unit is a sealed-bearing monolithic design (with an all-inclusive shell) so I scarcely get how it could have become compromised by dirt or the like.. The bike was ridden fairly hard, but not inordinately so.

Are ISIS BBs intended to have a rather stiff turning feel to them for some reason, or should it be gliding like a buttered marble on hot glass?