Ace 6.375 Mid 55 Truck – the first choice for robust quality. The Ace 6.375″ Mid 55 Truck is a classic 2.125″ (52mm) tall truck. When things get burly, Ace Pilots know, 55’s are the king of the session. Plenty of delicious hanger surface that lives to grind, coupled with an unbeatable geometry, there really can be nothing like it. Machine polished to a low luster. Ace’s polished finish trucks are the go-to choice when performance at no sacrifice is your goal.