The introduction of the ten-speed cassette is the small revolution in the shifting segment of the last two years. Sram got the ball rolling with the introduction of the XX groupset, with Shimano following suit later. The original idea was that the ten-speed cassette would save a front chainring without significantly reducing the gear range. 20 gears are enough for mountain biking, both for racing and touring. The advantage lies not only in the weight saving but also in simplified shifting or reduced chain wear.