Bicycle for indoor sport - has hub with large diameter and thick walls, and large spoke flanges

摘要

The bicycle is used indoors. It has an aluminium hub (18). The hub diameter (4,31) is large, and it has a thick wall. The spoke flanges (27,28) have a thickened section towards the centre and all holes (33) for spokes, are sunk on both sides. The spoke flange has a retainer flange (29) on the outside, with eight threaded bores, and a slide seat (30), to accommodate the drive pulley (19). Distance sleeves (20) and rings (21) are used to create space for single-double-row ball bearings of different sizes. ADVANTAGE - Gives rigid power transmission for moving forwards and backwards, easy and simple mounting of drive pulley without special tools.