Frame with split seat tube

摘要

A rigid bicycle frame arrangement comprising a split lower seat tube 9. This arrangement permits the use of a relatively short chain stay 5 resulting in a shortened wheelbase without compromising the geometry of the main members when using 29 inch diameter wheels. The split seat tube allows the rear wheel to partially enter the frame when rear wheel in brought forward reducing the chain-stay length and wheelbase. This arrangement permits desirable geometry of the frame members including seat tube angle, top tube length and seat tube offset. The shortened wheelbase of the bicycle using 29 inch diameter wheels results in desirable handling characteristics. The frame arrangement typically omits a front derailleur to allow the rear wheel to move into a forward position without fouling this mechanism.