rolliepollie

I'm looking at the 05 Specialized Allez Sport, and was wondering if upgrading the square-tapered bottom bracket and crankset is worth the extra cash (not sure exactly how much). Does a splined design really make a big difference in the stiffness? Also, I only weigh 135lb so maybe a square-tapered bb is stiff enough for me? Thanks.

jimbud

Shimano uses splined BB. Campy uses square tapered. I don't think there will be any difference between the two unless you have a preference for the make of components on the bike. Pros use both.

gcasillo

Stiff enough for these guys, stiff enough for you.

jhota

while i find the recent innovations in bottom bracket design impressive, what kind of gorilla would one have to be to cause flex in the shaft of any bottom bracket (that isn't defective)? if it was good enough for Coppi, Merckx and Lemond, it's good enough for me.

rolliepollie

Wow, didn't know Campy makes square-tapered bb's, and are used by racers - I'm such a n00b.

BarconsOrBust

I agree that square tapered BBs are dandy, and acknowledge that racers have used them for a long long time, but most of today's pro teams would be using outboard bearing systems, right? I'm being lazy and not doing the easy browsing to get my facts straight, but it seems to me that most teams that use Campy use FSA or similar cranksets with outboard bearings.

fsor

I have used square taper and octalink...I cannot tell any difference performance in them. Square taper needs to be correctly torqued or it can loosen and damage itself, but that isn't a problem given a little common sense. I have not (yet) used an outboard bearing system. I cannot compare to those.

cyclintom

The fact that square tapered bottom brackets lasted so long wasn't just a chance occurence.

Square tapers BB's have the strongest connection with the largest bearings. All BB's are a compromise but the square taper has withstood the test of time. Campy has the best engineers in the business and you'll notice that they remain with square tapers.

The ISIS and Octalink BB's have a stronger engagment but the bearings are a lot smaller. To get good bearing life they have to put in roller bearings which have high friction or you have to put up with shorter BB life.

In an effort to try to get the best of all possible worlds we're seeing crank makers using two piece cranks with external bearings for sufficient life and lowest friction.

As for me - I think Campy knows what they're doing.

John H.

Improper torque on the bottom bracket sleeves can result in damage to the BB whether it is square taper or octalink. Square taper cranks are probably less tolerant of under-torqued crankbolts than are octalink cranks, but again, neither is going to perform well under those conditions.