Rons

I have a 2012 Shimano 105 crank with about 500 miles on it. I'm just getting back into cycling. With the chain off the old Campy and Shimano cranks would spin forever. This crank is pretty tight with the chain off. Is that normal for the new style cranks? Thanks for any input.

jimc101

The HT2 BB does have more friction than square taper, but when riding, you won't notice it, and it has additional benifits over squre taper, that the crank arms don't profile with use, it's much stiffer than non external BB's, and it'e much easier to install.

TallRider

+1. The larger-diameter spindle and external bearings mean more bearing drag when tested under non-loaded conditions. When tested under load, the difference is near meaningless, and probably outweighed by the advantages of the newer design. Not a big deal either way though, which is why you won't find many people here who say you *must* have external-bearing design. Plenty of folks still use square-tapers.

Rons

Thanks guys. I suspected this but wasn't sure. It feels good when pedaling.

HillRider

I have the same crank and it does indeed have a bit more drag when first installed. However, 1) as mentioned you won't notice any difference when riding and 2) the drag will lessen as the miles accumulate and the seals wear in a bit.

GeorgeBMac

I have a 5600 series 105 crank and it still spins slower without a chain on than my Octalink Alivio crank even though it has loosened up a bit from when it was new. But it feels so much better than the Octalink. I can't put my finger on WHY it feels better, but it does. In fact, it spoiled me and I ordered a Shimano LX (HT2, external bearings) crank to replace the Alivio Octalink. There was no logical reason to do that. But, I tend to overdue it with bikes. It will be interesting how this HT2 crank feels after being used to the Octalink on that bike.

HillRider

I'd really like to know why. I have an Ultegra FC-6503 crank and matching BB-6500 Octalink bottom bracket on one bike and an FC-5703 crank with a Ultegra BB-6700 external bearing bottom bracket on another. I have identical Shimano 10-speed chains on both. Other than the gearing difference (52/42/26 vs 50/39/26) I can't tell any difference between them while riding.

GeorgeBMac

If it's not the additional stiffness from the external bearings then it might be the tighter tolerances on the higher end 105 crank... Or, it might just all be in my head -- it wouldn't be the worst thing up there!