Track Cycling: Velodrome Racing and Training Area - BB drop and BB height
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I'm a little...ok...A LOT confused about this. Are they one in the same? Whats the preferred measurement when track-frame shopping and why is it very important to a track bike's design and function? I think I understand the outside pedal clearance issue on a steeply banked track when slowing and moving up-track, but there's gotta be more to it than this, yes? Am I on the right track with this? (HA!...as my Filipino friends would say, "Ahhhh...you'rrre habing pun wit a pun! :D)
09-22-10, 04:22 AM
nope, not more to it. that's pretty much it.
BB drop and BB height are not the same, more of a yin and yang type thing. BB drop is the distance from a level plane between both axels, and the BB. BB height is the vertical distance from BB to ground.
What would be a proper bb drop and bb height measurement on a legal track bike? I've seen fg bikes that are trackbike-like in appearance and are probably perfectly suitable for roadwork, but I'm going to guess there'd be some pedal-strike issues on the banks of a track if the measurements are more road than track.
Is there an acceptable range for this measurement?...or is there only ONE bb height/drop measurement for legal trackbikes that is required?
09-22-10, 06:57 AM
Classic frames like the old Cinelli's and most NJS frames are right around 60 mm, while newer bikes, especially sprint bikes designed for 250m tracks with 45˚ banking are 50 mm or less. For comparison, most road frames are 68-70 mm I think.
That is about right. 60mm drop is the most you would want with a track bike with 165mm cranks if you are on a nicely banked track. 50-60mm drop would be fine.
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