Originally Posted by
justinzane
You may be right. Perhaps it is the data-geek in me that find the "personal preference" somewhat objectionable. If one is shopping for neckties, yeah, it really is down to personal preference since they no longer serve any functional purpose. For something as nigh-invisible and almost purely functional as a spindle with bearings -- all a BB is, after all, the fact that personal preference has any bearing seems odd.
There is minimizing friction, resisting radial and axial loads, resisting contamination and retaining lubrication, ease of maintenance and cost. I'm not criticizing you at all, since you probably know a lot more than I. I'm just frustrated with the lack of objectivity on this little part. If you want a rim, there are endless guides some with friggin' wind tunnel data! Folks have measured the stiffness of frames to the micro newton. Sh*t, people have even done wind tunnel testing on shaved legs and ponytails.
Yet, for something that EVERY cycle needs, whether the grandma's stepthrough utility bike or the $10k carbon and titanium triathlon bike, there is little definitive information. To ME, this seems odd. Maybe it is simply the invisibility of BBs that prevent them from being talked about and analyzed more.
Off to just ride and not thing about it...
I think that functionally, all will be pretty similar. I'm
not saying that there's no value in more expensive BBs. So some matters of preference are, do you want to spend more up front for a BB that will probably last longer and can be rebuilt rather than discarded? Do you want to spend more for lightness? Are you happy with old technology that works well and requires a minimal amount of routine maintenance? Do you want to spend your money because you want the newest whiz-bang gizmo?
If anyone were to do the test, it doesn't seem likely to me that he would find any significant difference in the amount of drag between various models and various technologies. There are likely differences in the durability of various BBs. More expensive ones are likely to last longer, but cheaper ones are... much cheaper. (As an aside, there's a very very good bike shop here in Pittsburgh. I'd bet that half the bike mechanics in town got some instruction, if not a complete education just by hanging out at Jerry's shop. The only square-taper BB he stocks is a UN55. I'm sure if you asked him to order a more expensive one, he would snicker at you and ask "whadya you wanna do that for?")
Anyway, back to durability, if someone wanted to test 20 units of every BB they could get their hands on, you might get some objective data about durability or maintenance requirements, but I don't think that'll ever happen, and if someone tried to do the test, someone else would complain that the test wasn't valid for one reason or another, another person will tell you that the added durability of the best performer is worth the extra cost and someone else will tell you they bought the cheapest one they could find and used it for 10 years on mud trails in Alaska before they had to replace it. So I come back to my assertion that you pay your money, you take your choice.