All variants are mated to a 5-speed torque converter gear box. Transmission was upgraded to a four speed gear box. The engine and gear box formed a single unit. Both engines are mated to a 5-speed manual gear box. This was coupled through a fluid flywheel to an epicyclic preselector 4-speed gear box. Baby customers could specify as an option a Wilson pre-selector gear box. The final drive in the gear box was changed to 25/27 ratio for improved performance. Most modern manual-transmission vehicles are fitted with a synchronized gear box. The only stipulation Chapman had was that a Renault gear box was used. The TS was fitted with an all-synchromesh four-speed gear box. As a small bore enduro bike it is equipped with a wide-ratio gear box. Later machines use a gear box driven by a dedicated electric motor. Both vehicles have a 5-speed gear box and a 2-speed transfer box. The gear box is combined into one block with a planetary steering gear.