Steel idler wheels replaced the wooden idlers fitted to French examples. Products include idlers, pulleys, belt cleaners and conveyor related accessories. Steering involved upright steering levers to four hydraulic brakes on the sprockets and idlers. The undercarriage consists of rubber or steel tracks, drive sprockets, rollers, idlers and associated components/structures. The drive sprocket was in the front, but there were no idlers or return rollers. All Ae 8/14 were double-locomotives with eight driving axles and six idlers. Idlers add friction and a potential point of failure to the drive train. Like the controlled differential, the brakes are normally applied to keep the idlers fixed. On education, Fourier felt that "civilized" parents and teachers saw children as little idlers. Coffeehouses drew together distinct groups, including academics, idlers, business men, and government officials. Humorous flax pulling songs make fun of idlers. This transport option is also powered by idlers.