>>1435343maybe my sample size is messed up
but amongst the hundreds of bikes I have encountered a common point of failure is the bottom bracket
the 35 mm BB being either slightly grumble from pitted bearing races and chipped balls or completely fucked from rust
where as the 51 mm BB seem to be able to sustain much more abuse before they become unusable (maybe the axle has more leverage over the bearing surface ?)
in either case cartridge bearings last longer but are not really intended to be repairable
I'm only coming at this from the perspective of end life / modes of failure
there are all sorts of factors involved
.eg smoothness, internal friction, consistency of alignment , load bearing ability
and I'm not qualified to make statements about exactly how ball bearing size effects such things
but I do find it interesting that bikes are moving to larger diameter bearing sizes anyway
