Bottom Bracket standards

[fossyant]

And now SRAM release DUB on top of all their other 'standards' Bonkers.

Best BB's have been Shimano threaded cassette bearings - literally fit and forget. External bearings are more prone to dirt and water, GXP being the worst for longevity, and pressfit/BB30 - argh - not easy to get rid of creaks. Shimano hollowtech/campag ultratorq seem the best external bearings.

I've re-greased my GXP at least 3 times in 2 years (OK not bad) where the cassette BB's can't be touched.

 

[chriscross1966]

Is there any room for bearings, or is it an external setup like HT2?

They're external, like HT2 or Ultratorque .

 

[Nigelnightmare]

I've heard of people complaining about threaded cassette bearings becoming seized in the frame!!
This is only because they last "Soooo Long" without any problems that they're forgotten about...……..

………..Until they want to upgrade to something "newer/better" that will need fettling/maintenance/replacing frequently.
OR get a new crankset that's not square taper!

I'm not a Luddite BUT what was wrong with the old "easy to maintain/service" cup & cone bottom brackets?

 

[Gravity Aided]

Not much wrong with the old cup and cone system if maintenance was performed, which lets out about 95% of the cycling public.

 

[Ajax Bay]

what was wrong with the old "easy to maintain/service" cup & cone bottom brackets?

Like the man said (edited): "BB history: Cotters were problematic but were eventually replaced by the square taper, which was brilliant. It allowed lightweight aluminium cranks to be securely fastened to steel crank spindles without any problems of precession and lash, both problems with the cotter. (Note that I'm referring to a British cotter, not American cotter). Then the weight weenies came around and questioned the solid BB axle and asked for something to be make lighter."
If you haven't, read the quote from @Yellow Saddle
The cup and cone bearings are just 'too heavy': that's what's "wrong". Actually the cartridge screw-in square taper bearings are pretty long lasting and easy and cheap to replace - given their longevity, entirely reasonable to dispense with cup & cone (though I'm keeping my 70s Campagnolo BB on my old bike, for old times sake).
As far as heaviness is concerned, as part of looking for a shorter crank option for 'a bit short' offspring's TT bike (4:15 for a half Ironman), I worked out that a Shimano Compact chainset with Hollowtech2 BB weighed a grand amount of 140g less than a Spa Cycles square taper chainset using a UN55 cartridge BB. 140g weight saving! That's one decent swig from a bottle (though of course one's nat 'saving' that, just moving it from on the frame to close to the bike/rider's centre of gravity).

 

[rogerzilla]

Cup and cone BBs usually died through water ingress and pitting. They were never very well sealed. I have one on my 1990(ish) Ron Cooper but that's a dry weather bike.