Q Factor (Bicycles)
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The Q factor of a bicycle is the distance (measured parallel to the bottom bracket axle) between the pedal attachment points on the crank arms. It may also be referred to as the "tread" of the crankset.
Q factor is a function of both the bottom bracket width (axle length) and the crank arms. Bottom brackets axles vary in length from 107mm and 127mm. MTB cranks are typically about 20mm wider than road cranks.[1]
It is claimed that a narrower tread is ergonomically superior because it more closely matches the nearly-inline track of human footsteps.[2] A narrower tread is also desirable on faired recumbent bicycles because then the fairing can also be narrower, hence smaller and lighter.
A wider tread will mean less cornering clearance for the same bottom bracket height and crank arm length.
[edit] References
- ^ The Q-Factor. Retrieved on 2007-02-25.
- ^ Sheldon Brown's Bicycle Glossary. Retrieved on 2007-02-25.
