All full-suspension bikes will generate some pedal kickback due to chainstay growth during suspension compression. Kickback occurs when the rear suspension compresses and causes the chain to tighten, pulling the crank arms backward. With the rider’s weight on the cranks, these forces transfer to work against the suspension as it tries to compress, reducing its effectiveness. This effect is amplified when descending in rough and technical terrain, producing less consistent suspension movement, reduced traction, and a harsh ride. 

Pedal kickback varies on every bike depending on speed and gearing, so it also reduces the predictability of suspension performance. Seemingly random inputs to the pedals and intermittent harsh suspension movement can confuse the rider and reduce control, as well as make suspension setup problematic. 

e*thirteen’s Sidekick hub addresses this issue by adding an adjustable deadband to the hub engagement that decouples the drivetrain from the suspension, eliminating the problem at its source, so chainstay growth never causes tension in the chain.