is hollow tech better than square taper bb / cranks?

[02gf74]

Yeah, ive nothing against square except maybe difficulty of pulling cramks off.

Hollowtech 2 in theory is cheaper to replace bearings, yes it can be done, the cheaper sealed bearings are wider than prooper onez so need the plastic seal/cover to be trimmed.

 

[mattr]

I was referrring to octalink, i thought that was also known as hollowtech 1.??!?

Ive replaced square taper bb with hollowtech 2.. . So an i but cinfysed as i thought there was one diameter

octalink is the bottom bracket standard, hollowtech refers to the crank. Hollowtech II is a double whammy. Not only is it the second generation, it's a 2 piece crank.

And I'm talking about axle diameters, square taper is smallest, then octalink, then hollowtech II (then loads of new and huge standards).
Octalink was a bit flawed cos they kept the bearings inside the shell. Big axle. Small balls. HTII they went back to bigger balls.

 

[eshew]

Square taper is noticeably less stiff than a Hollowtech II crank. Rather than axle flex I think the real culprit is outward tapering square axles compared to a flat 16 point axle. The torque from pedaling is directed at the connection points more effectively with a Hollowtech II than the outward tapering square axle where force can migrate along the taper outward to the 8mm bolt.

Add to that a larger diameter hollow axle is larger in diameter and wider gives a much more solid connection. Again Hollowtech wins.

The downside is outoard bearing bottom brackets, due to their out board bearings being smaller in diameter, will fail sooner. However, the chain rings for the newer cranks are much more plentiful and cheaper... In addition, since you've gone non retro in one regard, you can feel free to go to 9 or 10 speed with a clutch & new faster shifters...

That and XTR repalcement BB's are cheap.

A note though, unlike square taper bottom brackets the plastic screw for the non drive side crank arm doesn't need to be very tight. One of the major contributors to short bearing life in shimano outboard bearing BB's is too much side load caused by over tightening this plastic nut. Similar a headset cap, it should be used to make sure the crank arm is fully seated & then backed off a bit and use the 2 bolts on the crank arm to make sure the arm stays put.