Shimano 8, 9 & 10 Speed Cassette Compatibility With 11 Speed Freehub

The Dura-Ace CS-9000 & Ultegra CS-6800 HG-EV 11 Speed Cassette is 1.85mm wider than a 10 speed HG cassette, therefore the freehub dimensions have been adjusted accordingly. In order to mount a CS-9000 or CS-6800 HG-EV 11 speed cassette, an 11- speed wheel must be used.

When mounting a 10-speed cassette on the new 11-speed freehub design 2 spacers are required. Firstly a 1.85mm spacer which is supplied with the wheel, secondly a 1mm spacer which is supplied with the cassette.

To run an 8 or 9-speed cassette, only the 1.85 spacer is required.

Shimano Original Parts
1.85mm Spacer Part No. Y4T724000 £3.99
1.00mm Spacer Part No. Y1Z807000 £1.99

Shimano 9 & 10 Speed Cassette Compatibility With 11 Speed Freehub