Patent ID: 7022037

Claim:
Gear assembly for a bicycle gear change, comprising at least one gear with a larger diameter ( 28 ) and at least one gear with a smaller diameter ( 30 ), said gears being destined to cooperate with a chain ( 16 ) shiftable from one to the other of said gears ( 28 , 30 ), to perform a gear change, characterized in that said gear with a larger diameter ( 28 ) comprises at least one sector dedicated to upwards shifting ( 44 , 46 ), including shifting aid means ( 52 , 54 , 56 , 58 ) to facilitate upwards shifting, and at least one sector dedicated to downwards shifting ( 40 , 42 ) including shifting aid means ( 50 ) to facilitate downwards shifting, wherein said at least one sector dedicated to upwards shifting ( 44 , 46 ) has a larger angular extension than said at least one sector dedicated to downwards shifting ( 40 , 42 ); and wherein the ratio between the angular extension of said at least one sector dedicated to upwards shifting ( 44 , 46 ) and the angular extension of said at least one sector dedicated to downwards shifting ( 40 , 42 ) is between 1.5 and 5.