If you could get the BB and the rider down four inches then that would definitely be noticed. Pedal strike might be an issue though!!
. This is where dropper posts have been used effectively, on Occassion, in the pro peloton for crazy downhill madness.
What makes me think the relatively small differences of BB heights between cruterium/road/CX/TT/touring/MTB/gravel bikes is not making any real difference is when you see CX riders stand on the pedals , when the cranks are horizontal, and lift themselves out of the saddle to negotiate some sketchy terraiin. The kind of rutted, lumpy, bumpy downhill that would make me wish i was sitting in the triangle and not above it! .
You see the same thing with pro road riders who when descending will lift there weight off the saddle, when braking, but not just when they are braking in an straight line for a hairpin, for example. Ben Healey is a really good descender and he does it a lot and i noticd some of the women doing it, too, during the womens Tour. It was either that young frenchie who won a couple of stages, or Prevot herself.
It has got me thinking that there might be some kind of sweet spot that makes it all feel amazing and that it might be dictated by body weight ,and where that weight is spread around the body affecting the CofG, the riders height effect on frame size and CofG and also where the rider sits between the wheels which also affects CofG. This fore and aft thing is very important in the world of aeroplanes, for example . It could be that riders and bikes with particular proportions notice small differences in BB height/drop, and riders with different proportions are less affected. I think i am saying that it is a fluid thing and not set in stone that a particular BB height is going to be better than another as there are so many other parameters that can be adjusted, on the fly.
