A modified 8 Speed Spike 1- It uses an integrated electric motor system . It features a 350W Geared Hub Motor, a special Crankset with sensors, a 36V 13 AH Rack Mounted Battery with built in light, and a Digital Display. With this system you can choose between manual, throttle only or 6 different levels of pedal assist. The 36v 13AH battery is much larger than other manufacturers use and will give you a much longer range- about 30 miles electric only and up to 75 miles using pedal assist. This model includes Schwalbe Big Apple 20 x 2.0 Tires , Microshift Trigger Shifter, and Avid BB7 Brakes.