Complex sentence: Some Brompton suppliers offer a 2-speed chainring'Mountain Drive' as well, which results in 12 distinct gear ratios with a range exceeding 5:1; in this case, the change from 6th to 7th gear involves changing all three sets of gears simultaneously.
Split into simpler sentences: Some Brompton suppliers offer a 2-speed chainring'Mountain Drive' as well, which results in 12 distinct gears with a range exceeding 5:1. However, the change from 6th to 7th gear involves changing all three sets of gears simultaneously.