Complex sentence: The climbs of the Ruppershain, Feldberg and Mammolshain are regular features; the Mammolshain has a maximal gradient of 26% and is climbed twice in the race.
Split into simpler sentences: The climbs of the Ruppershain, Feldberg and Mammolshain are some of the regular features. The Mammolshain has a maximal gradient of 26% and is climbed twice in the race.