Reports of the demise of this Web site are greatly exaggerated! We at sheldonbrown.com thank Harris Cyclery for its support over the years. Harris Cyclery has closed, but we keep going. Keep visiting the site for new and updated articles, and news about possible new affilations.



find us on FB

More Articles by Jobst Brandt
Next: Frames "Going Soft"
Previous: Bike Pulls to One Side

spoke

Subject: Bottom Bracket Drop
From: Jobst Brandt
Date: July 10, 2000

I'm not familiar with BB drop. How is it measured and what are its limits?

For road bicycles, using conventional sized wheels, BB drop (BB spindle centerline below wheel axle centerlines) has been empirically arrived upon at about [240 mm minus crank length] for useful cornering clearance. Imbalance of pedaling in curves at greater lean causes side-slip. For this reason, higher BB's have shown no advantage in criterium racing while road races are practically unaffected by maximum cornering ability while pedaling.

Track bicycles have certain advantages on tracks with steep banking if they can ride the curves at zero speed but then that depends on track length and how it is banked.

Jobst Brandt

Spoke Divider

More Articles by Jobst Brandt
Next: Frames "Going Soft"
Previous: Bike Pulls to One Side

Spoke Divider

Spoke Divider

Articles by Sheldon Brown and others
Harris
Home
Beginners Brakes Commuting
Lights
Cycle-
Computers
Do-It-
Yourself
Essays
Family
Cycling
Fixed Gear
Singlespeed
Frames Gears &
Drivetrain
Bicycle
Humor
Bicycle
Glossary
Bicycle
Links
Old
Bikes
Repair
Tips
Tandems Touring What's
New
Wheels Sheldon
Brown

Reports of the demise of this Web site are greatly exaggerated! We at sheldonbrown.com thank Harris Cyclery for its support over the years. Harris Cyclery has closed, but we keep going. Keep visiting the site for new and updated articles, and news about possible new affilations.

Harris Cyclery Home Page

If you would like to make a link or bookmark to this page, the URL is:
https://www.sheldonbrown.com/brandt/bb-drop.html

Last Updated: by John Allen