This causes the hub to momentarily dip down within the wheel by up to 45 millimeters, so it’s actually a bit off-center until the springs flex back into their regular state. For this reason, the wheels will only work on bikes that already have sufficient space between the fork/frame and the tire – otherwise the bike would be hitting its own tires when the springs compressed.
“Selective suspension is the key to the mechanism because constant suspension creates loss of energy, making pushing more strenuous. Only when encountering an object does the suspension system activate, making the inside of the wheel, the hub, move and absorb most of the shock instead of the wheelchair user’s body,” she said.

The Loopwheels’ spring system between the hub and the rim cushions the rider from potholes and bumps in the road. It also reduces road noise by absorbing it, thereby reducing vibration through the frame—and into the rider’s arms and body. Because the suspension is inside the wheel, you don’t need fat tires to make the ride nicer. Instead, you can use high-pressure or puncture-resistant tires.
A trailing arm is attached to the wheel hub at one end, and extends forward to a pivot on the frame.