SPROCKET CLUSTER FOR BICYCLE, MULTI-STAGE SPROCKET DEVICE FOR BICYCLE, HUB AND SPROCKET DEVICE FOR BICYCLE, AND CHAIN AND SPROCKET CLUSTER FOR BICYCLE

摘要

PROBLEM TO BE SOLVED: To increase the number of sprockets which can be installed by setting a gap between the adjacent prockets small in a sprocket cluster for a bicycle. SOLUTION: A sprocket cluster 100 for a bicycle is provided with plural sprockets F1 -F4 concentrically installed at an axially decided position. A free space (f) is formed between a teeth bottom diameter part at the smaller diameter sprocket and an axially parallel part to the teeth bottom diameter part in the larger diameter sprocket. A gap at least equal to thickness of one sprocket or less is formed between the adjacent sprockets.