What is Front-Center?
The distance from the center of the bottom bracket to the center of the front wheel axle. This measurement is taken from the side view of the bike, ignoring the z-axis such that the width of the axle or bottom bracket does not come into play.
Why is it important?
Front-Center affects the rider's weight distribution and bike handling when climbing and descending. It can also give an indication of when toe overlap might be present.
A longer Front-Center increases steering stability when descending and keeps mountain bikers from going over the handlebars when the front wheel hits bumps or the fork compresses under braking. However, a Front-Center that is too long will make it difficult to keep enough weight on the front of the bike when climbing, resulting in wheel lift and tire deflection.
A bike that is too small for a rider will likely have too short a front-center and a bike that is too large for a rider will likely have too long a front-center. Even if the rider’s position can be adjusted for by the use of a different stem or handlebar, the front-center is fixed for a given frame and fork. This is one of the reasons why it’s critical to get the right size bike for a rider rather than trying to make a poor fit work with a different cockpit setup.