EBR 1190RX just unveiled

Quote:

Originally Posted by David Branyon

Moment of inertia is pretty easy to calculate for simple shapes like a disk. If someone wants a comparison run, provide the inner and outer diameters and thickness, # of rotors, and material (assuming it's all stainless steel) and I'll do the calcs. Can't remember the formula off the top of my head but have it at work. So provide that info for the rim brake disc on the Buell and for some comparison dual disk regular bike and I'll work up the numbers. The formulas is an elaborate version of integral (mr^2), so the radius piece is pretty strong and I'd guess the rim brake is likely higher in inertia.

That will tell you the difference in MOI of the disk, but doesn't take into account that the Buell wheel is lighter in the hub and spokes (since the braking forces act directly on the rim). The most accurate way to calculate the combined wheel/disk/tire MOI is to do what they did in the Sport Rider article I posted: "Each wheel was mounted to an axle and rolled down an incline of a known slope. The amount of time it takes for the wheel to roll a set distance from a stop is used (along with the wheel's weight, the slope angle and the axle diameter) to calculate the wheel's MoI."

Read more: http://www.sportrider.com/gear/146_0...#ixzz2lmGhZ4dL