Shimano and Sram specific 40T sprockets have been designed, this gives us the following benefits which wouldn’t be possible with a larger sprocket size or with a universal type design: 1. Precise matching of the tooth profiles and shifting points specific to each cassette 2. Perfect mating of supporting tabs reducing flex and aiding shift performance 3. Lower B-tension adjustment is needed ensuring good shifting throughout the cassette range compared to fitting a 42t Installation Notes Note 1: For a 1 x 10 set-up with a newly converted 11-40 cassette you will need a rear derailleur with a 29T capacity [ 40-11=29 ]. For a 2 x 10 set-up with 40/28 chainrings and a newly converted 11-40 cassette you will need a rear derailleur with a 41T capacity [ (40-11)+(40-28)=41 ]. Note 2: In most cases we recommend removing the 17T sprocket. In the case of the Shimano CS-M980 and CS-M771-10 this is the only sprocket that can be easily removed. In the case of the SRAM PG-1030, PG-1050 and PG-1070 it is possible to remove alternative individual sprockets. Note 3: If your B-tension screw is not long enough use the supplied M4 x 20mm screw. Refer to the manufacturer’s instructions for further guidelines on adjusting your rear derailleur. Note 4: With the chain mounted on your largest front chainring and the 40T-REx sprocket, check that your chain is not being pulled tight. If your chain is not long enough, replace it with a new longer one…
– Hope T-Rex Ratio Expander Sprocket Cassettes & Freewheels – £51.98 (RRP – £)
