Design Goals:

The drivetrain must efficiently transmit power from the engine to back wheel while satisfying all design and realistic constraints as best as possible. A more efficient drivetrain will ensure the overall goal of the competition to minimize the amount of fuel used to propel the vehicle.  A reusable drivetrain would be preferable to aide in success of future iterations of Supermileage at TCNJ as the competition becomes a perennial project for the school.

Primary Drivetrain:

The transmission chosen is the Nuvinci Harmony 380 Innovation Kit donated by Fallbrook Technologies Inc. It is laced as a hub into a bicycle wheel, and will be utilized on the rear wheel of the vehicle. A chain drive will be implemented from the clutch to the Nuvinci Harmony 380 rear wheel hub. The N380 works by using a set of spheres contained within the hub that are angled using a shifter to alter the gear ratio to ensure that the engine remains running at its most efficient output speed. The CVT allows for a range of ratios from 0.5 underdrive to 1.9 overdrive.  a standard 3/32 inch bicycle chain will be utilized for the gear reduction. The clutch chosen is the 10T, 3/4″ bore, Max Torque Centrifugal Clutch, #41. To ensure proper chain tension, an idler sprocket and chain tensioner assembly.

Secondary Drivetrain:

As a backup, a single stage chain drivetrain has also been designed, and may be made in case of failure of the primary transmission while at competition, or if it is deemed inadequate after testing. It consists of the proposed clutch with a 10 tooth sprocket, the proposed chain tensioner/sprocket assembly, a large rear wheel sprocket, a reversible rear wheel hub and ANSI #25 chain. A rear wheel sprocket with 80 teeth was selected. The reversible rear wheel hub to be utilized is the Antigram Cassette Hub.