da Vinci’s Independent Drive
The Independent Coasting Advantage
da Vinci Designs’ Independent Coasting System (ICS) offers you a riding experience both on and off road that equals or surpasses the best you’ve had on a single or tandem bike. The ICS makes for a far more intuitive, comfortable and efficient ride. This newfound ability to independently or collectively coast, pedal and position your cranks at will offers these advantages:
- Starting, stopping and going through corners are as easy as on a single bike.
- Captain and stoker can independently relax, take a drink, adjust seat position, stand for a few seconds to relieve weary sit bones, even take a moment to gaze at scenery, while the other keeps pedaling.
- Traversing obstacles is easier and more efficient because the captain and stoker can coordinate avoiding the obstacles while maintaining forward momentum.
- Asynchronous pedaling decreases strain on the final drivetrain.
The main component of da Vinci Designs’ ICS is an intermediate drive shaft six inches in front of the rear bottom bracket. The intermediate shaft has two single-speed freewheels on the left side that are independently driven by the cranks at twice the rotating speed and half the torque. On the right side of the shaft, four Hyperglide cogs drive the bike. The chain rings are half the size as those on a conventional tandem because of the double rotation of the intermediate shaft. The combination of 12-, 18-, 24-, 30-tooth driving gears equals 24-, 36-, 48-, 60-tooth chain rings. The combination of the small 6-tooth gap, doubled rotation and the Hyperglide cogs gives da Vinci Designs’ tandems these technical advantages:
- Smooth and fast front shifting – The closer the chain rings are to the same size, the easier it is to shift. Other tandems, and even single bikes, are forced to use a 12-tooth gap between chain rings.
- Unprecedented range of gears – Four chain rings and eight rear sprockets mean 32 gears that range from 18 to 140 gear-inches. No other tandem gives you that many gears or that kind of range.
- More ground clearance – Nice when you lift your tandem over a curb, out of a truck, or when you are off road.
- Stronger, lighter chain rings that are less prone to bending
- Less strain on the chain while shifting