TECHNOLOGY

High Performance Bike with Interconnected Suspension

This clip describes a prototype bicycle with interconnected suspension, the aim of which is to significantly reduce the stiffness of the suspension so that shocks transmitted to the rider can be greatly reduced. The clip describes the features that make this achievable - high anti-dive, high anti-squat (to stop bobbing) and high recession angles (to further reduce shock transmission), without which the low suspension stiffness would not be practical. The result is a bike that can be ridden faster across bumpy tracks with the additional benefit of less rider fatigue.


Why have Interconnected Suspension on a Bike?

This short movie explains why interconnected suspension (likened to a railway bogie) can be used effectively to significantly reduce the shock loads transmitted to a rider and to improve the tyre's (especially the front tyre) contact with the ground to greatly improve steering control. The film describes how the instinctive reaction of a rider of a rigid bike, when encountering a series of bumps, is to stand on the pedals and, holding the handle bars loosely, allow the bike to traverse the bumps like a bogie. The idea of interconnected suspension is to reproduce this motion without the rider having to transfer their weight off the saddle.


Recession Angles, Anti-Dive and Decoupled Brakes

The way in which the wheels move as a consequence of hitting a bump, along with the suspension stiffness/damping, determines the level of shock experienced by the rider. So if the wheel centre moves back, shock is reduced and vice versa. The way in which the contact patch moves (with the brakes applied) determines the amount of dive that occurs. For high anti-dive, the rear contact patch should move up/back (same as the wheel centre) and the front, up/forwards (opposite to wheel centre). To get the best of both worlds the front contact patch movement can be "decoupled" from the wheel centre movement using a special arrangement of the brakes - described in this movie.


Interconnected Suspension Bike Transmission

Bobbing occurs as a result of cyclic variation in torque (twice per revolution of the crank). On a conventional suspension bike, anti-squat can be used to prevent bobbing at the rear, but at the front the only way of reducing this unwanted motion is to have stiff suspension and/or high levels of low velocity damping (which is not good for ride). With an interconnected bike, pitching can be eliminated altogether. The film describes, using the analogy of the bogie, how this is achieved. This is key to allowing the front suspension stiffness to be much lower than normal with all the attendant advantages of steering control, tyre/rim protection and reduced rider fatigue.


MB Suspension Technical Paper

MB Suspension Technical Paper (PDF document which requires Adobe Reader)

Please also see the Technical Paper in PDF format, available for download here:
MB Suspension Technical Paper