Question: Is there any advantage of an Ochain setup on a eMTB? – Brad, Lakewood, CO
Answer: The Ochain setup is basically a component (active spider) installed between the crank and chainring that reduces pedal kickback by allowing the chainring to rotate backwards independent of the crank. This allows the rear suspension to full compress which results in less feedback to the rider through the drivetrain. Normally when the bike hits a bump and the suspension compresses, the rear wheel’s movement pushes the chain forward which pulls the chainring backward, causing the cranks to rotate backward (pedal kickback).
The Ochain setup became popular in downhill mountain bike racing a few years ago. A popular rider broke his bike chain on the course during a live race and saw his split times improved without the tension in the chain holding back the rear suspension travel.
An Ochain active spider reminds me of a motorcycle’s slipper clutch in that it isolates the drivetrain from the suspension by allowing controlled rotational movement. While a slipper clutch uses an internal mechanism to slip under engine braking on a motorcycle, the MTB Ochain uses a spring-loaded, multi-plate system to allow the chainring to rotate backward.
Ochain’s in theory should help downhill eMTB’s even more by isolating the transmission from the suspension like a slipper clutch does with a motorbike during engine braking. Ochain E & Ochain S are designed to be compatible with popular e-bike motors from Shimano and Bosch. Ochain models for eMTB’s typically come with a fixed 9-degree setup, which is considered the best compromise for ebike performance and durability, although some models allow for switching degrees of float with additional elastomer kits.
Ludwig Von Heinrich (AKA Dr. Dirt) is a German-American born PHD engineer, cycling historian and author who serves as our experienced mentor on all things bicycle. Dr. Dirt has cycled on all 7 continents (yes even Antarctica!) and has been credited with repairing over 10,000 bikes over his career. Dr. Dirt was an early fan of e-bikes and even had one of the first Montage folding e-bikes from the early 1990’s.
While not on staff Dr. Dirt does provide valuable guidance, motivation, and feedback for what we are trying to accomplish here. If you have a cycling or e-bike question please drop him a note at drdirt@dirtrevo.com.