Road Bike Bottom Bracket Height

There is nothing magical about the bottom bracket height relative to the axle height a bike does not hang from the axles rather it balances upon the tires.

Road bike bottom bracket height. Cyclocross bikes earned a higher bottom bracket back in the days when racers competed with clips and toe straps. In fact chris porter of mojo suspension comments in this article on how he feels that 29er wheels place the bottom bracket so far below the wheel axles that it makes it difficult to get enough weight over rather than behind the front wheel when braking. Multiply that figure by 0 883 and that according to the lemond method will produce your saddle height again from the centre of the bottom bracket to the top of the saddle though burt says it. Locating the optimum saddle height is pretty much the foundation of bike fit the distance between the bottom bracket and top of your seat plays a role in comfort as well as power output and.

A road bike typically has a bottom bracket drop of approximately 70 74mm. Initial geometry points revolve around the bottom bracket height wheel size and suspension requirements. It is the measurement from the center of the bottom bracket to any level surface that the bicycle is sitting. A 54cm specialized tarmac road bike has a 268mm bottom bracket height while a medium sized specialized hardtail expert mountain bike with front suspension only has a 309mm bottom bracket height and a medium specialized epic expert carbon with both front and rear suspension has a bottom bracket height of 332mm.

The standard on a road bike used to be 70mm. This measurement can change because fatter tires will raise the bottom bracket height. Contrast this with a typical drop of 55 65cm for popular production cross bikes.