Bottom Bracket Height

What is Bottom Bracket Height?

Bottom Bracket Height is a measurement taken vertically from the ground up to the center of the bottom bracket. This measurement will vary depending on the tire used on the bike. If this measurement is not provided in the brand geometry table, we calculate an estimated bottom bracket height based on the diameter of the base wheel and tire specification. To see the estimated Bottom Bracket Height for a different wheel and tire combination, use the Configure Build option.

Since this estimate derives the tire's height from the nominal width of the tire, real world Bottom Bracket Height may differ.

Why does it matter?

Proponents of a low bottom bracket claim that handling is improved by lowering the rider's center of gravity which improves stability and provides more responsive rear-end handling (steering with body weight). This also places the saddle closer to the ground which makes mounting/dismounting easier and makes it easier to put a foot down at stops.

Some bike designers argue that the effect of shifting the center of gravity lower is negligible and is outweighed by the advantages of a higher bottom bracket. For applications where pedal strikes are anticipated (offroad/crit racing/track bikes/cyclocross/riders with long crank arms) a higher bottom bracket is desirable to give more pedal-to-ground clearance.

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