is hollow tech better than square taper bb / cranks?

[ultrazenith]

I'm about to build a rigid Salsa El Mariachi, and would like to keep a retro flava to it, so might go with a square taper bb and 5 bolt low profile chainset. Is there any good reason to choose hollowtech instead? Is it just a bit lighter, or is there some increase in stiffness (I find it hard to believe a solid steel axle would be less stiff, but what do I know).

 

[andyz]

Re:

Hollowtech is a bit stiffer and easier to take apart, but square taper will last much longer.

 

[brocklanders023]

Re:

As above. Both have good and bad points but not to make much difference. The benefit to hollow tech is the variety you have from cheap to mega bling.

 

[pete_mcc]

Re:

Have it all - Bullseye cranks; retro, hollow tech and thru axle

 

[02gf74]

The central part of any axle adds very little to stiffness, so for the same weight a tube is stiffer than solid rod, obviously for the same material the tube would be larger diameter.

Pretty sure the higher end shimano square taper axles are hollow, same or better strength than cheaper ones due to better metal.

One thing i discovered on a road bike is hollowtech bb is larger diameter than square.

 

[RickTheUncivil]

i believe hollowtech have smaller bearings (to fit the larger axle in the same shell) so I guess thats the weakness.

by hollowtech do you mean hollowtech spline drive thing or hollowtech 2 with the gaping tube through the axle and the axle fixed to one crank?

 

[M-Power]

Re:

I'm a big fan of quality retro square taper. Nowt wrong with it and it's bomb proof. I'm thinking Syncros steel or if you wanna save weight Ti version. Plus it will hold its value if it's pulled in decent reusable shape.

 

[mattr]

I found the top end serviceable octalink (hollowtech) bottom brackets to be (so far) the most durable of anything i've ever had.
I've got three of them, all in perfect working order, two outlasted the cranks they were bought with, one has done about 8 seasons of all weather mtb riding/racing/training and has now been "retired" to my retro bike. Still runs like new. Got a D-A bottom bracket in my cross bike now. Still spinning very nicely on it's yearly inspection and clean. Must have done over 80000 miles. :shock: I've heard that a lot were mangled by hamfisted mechanics (tiny balls instead of 1/4" or square taper) one reason for shimano to drop them.
Serviceable square taper (shimano and campag) would do maybe two-two and a half years hard use (so 3 or 4 strip downs and rebuild) before they got beyond economic repair (new axle needed, or corrosion after a bad winter, or something that made it more practical to buy new), or got sold on with the frame.....

Sealed square taper was always disposable, 12-18 months of use and they'd be ready for the bin. Didn't seem to matter what level they were. Anything from XTR, down to deore. Start to get a bit wobbly or gritty after a year or so use, and depending on budget they'd die anything from almost immediately, to 6 months later. Seal octalink was better, but still only 2 years or so. Think the bigger axle helped with off axis running you get with the skinnier axles.

I'm not riding anywhere near as much these days, (more like a couple of thousand km a year instead of monthly........) so the HTII/external stuff i have, even though some of it is 10 years old, hasn't done a huge mileage yet...... but still a lot more than some who destroy them in days/weeks. Probably cos i fit em properly.

And from what i remember the octalink axle was a 24mm tube, square taper was 16 or 18mm, so a lot less stiff. The octalink interface was more effective too. Less stretch, wobble and flex.

TLR
octalink is slightly better/more durable than square taper, serviceable Octalink lasts for ever, but is a bugger to find these days.

 

[02gf74]

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

 

[jimo746]

I've honestly found no difference in "real world" riding.
Any weight difference is unnoticeable once it's fitted.
Any extra axle stiffness is unnoticeable, especially compared to crank stiffness.
Both need tools to fit/remove and are both pretty simple to do.

I'd probably decide what cranks/chainset you want, and just get whatever bottom bracket works with them, if it's square taper then so be it.I use cheaper Shimano square taper BB's and treat them as disposable (for the reasons I listed above), I'm reluctant to try a Ti BB again as I had no end of creaking woes with the last one.