padawan said:
I'm considering buying an FSA K-Force crank with their titanium ISIS BB. I've heard the Mega EXO external BB is better (but how much) but is the TI ISIS BB still quality or have their been problems with it. If I can get a good deal on this high end crank paired with the TI BB will I be happy?
I'd be interested in hearing good or bad about this BB if you have any kowledge of it.
Many thanks!!
Pad
ISIS is good quality, but because of the smaller bearing size, ISIS or Octalink are inherently less long-wearing and have higher friction. Their advantage when they first came out was lighter weight vs. square taper and stiffer because of the large hollow axle. Outboard bearings (such as megaEXO) use larger bearings and have lower friction and the whole setup is generally stiffer still. Weight is about equal, depending on brand and model). The downside is that the BB shell faces must be parallel and there is less brand interchangeability (all ISIS should fit all ISIS, but not all outboard BB are interchangeable--although FSA and Shimano should be--Campy and Truvativ, not).
You will be happy with ISIS. Grand Tours were won on ISIS or Octalink BBs. Heck Square-taper is still good enough. I recently we with an ISIS set-up because of the low cost of ISIS stuff on clearance now that MegaEXO is out. Cost being equal, I would go with integrated MegaEXO type as that appears to be the new standard.
Incidentally, integrated bearings is probably a cheaper manufacturing cost for the companies because one bearing set can be used for both triple and double--kind of like the threadless headset idea where one fork fits all frame sizes. Just cut to fit.