Mountain Bike Seat Geometry

From top tube length to bottom bracket height mountain bike geometry can reveal plenty about how a bike will ride and whether or not it will fit you.

Mountain bike seat geometry. Head angle is the angle of the fork s steerer tube measured from horizontal. We also have the world s largest database of fitters. So if a bike had a 22 inch seat tube it was a pretty safe bet the top tube was similar in length. What mountain bike frame size should i ride.

Knowing the bike s stack how tall a frame is and reach how long a frame is will allow you to compare between different manufacturers and immediately know if it will fit you regardless of how it is described or what the seat tube measurement is. How to change your mountain bike s geometry. That s 8209 bikes from 778 brands and growing daily. Mountain bike head tube angle head angle or head tube angle is the angle between the front fork of your mountain bike and the ground.

This is the angle of the seat tube relative to the ground. Understanding how they interact will help you choose the right machine and unlock its potential. A bike s angles and dimensions are the key to the way it rides. Mountain bike geometry explained in 9 numbers.

Frames were more or less square with the top tube parallel to the ground and the top tube a similar length to the seat tube. A 130m 140mm bike with more balanced geometry would be much faster on normal trails than something like that. An 18 bike had an 18 seat tube and a 54 cm bike had a 54 cm seat tube. Tt and tri bikes.

Find a local bike fitter and get professional help. The two most fundamental elements of frame geometry are stack and reach. Narrower bars have the benefit of improving aerodynamics by reducing a rider s frontal profile but can be uncomfortable and create twitchy handling. Steep seat tubes are just a bandaid to make bikes with dh geometry pedal acceptably.

Getting the perfect mountain. For mountain bikes most companies have abandoned this sizing convention and for the few that still use it the numbers are meaningless i e an 18 bike doesn t actually have an 18 seat tube length. Bike geometry can be daunting but it doesn t need to be. Although most geometry charts measure the seat tube length to provide the frame size.

For mountain bikes where geometry is based on the aggressive riding standing position with the seat down reach trumps stack as the primary fit dimension. Traditionally this was the measurement that was used to state the size of a bike. Actual seat angle is the angle of the bike s seat post measured from horizontal.