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bottom bracket drop...(3 posts)

bottom bracket drop...phlegm
Aug 3, 2002 5:42 PM
So I noticed when looking at road bike geometry, the bottom bracket drop is often listed as 66, 70, etc. Obviously, the BB must be more than 70 mm off of the ground. What's the deal?
bottom bracket drop is measured.....gogene
Aug 3, 2002 5:55 PM
.....from an imaginary line drawn between the front and rear dropouts. Hence a 7cm BB drop is 7cm BELOW this line. A lower BB, to a point, is considered to make a bike more stable. A touring bike will have a low BB. A crit racing bike will have a higher BB, mainly for better clearance whilst cornering
thanks...phlegm
Aug 3, 2002 6:00 PM
That makes sense. Lower to the ground is more stable.

This 2002 Lemond catalog has BB to ground measurement labeled as the BB drop.