I am trying to design a small-scale way to turn bicycle tyres into rubber crumb, as is done on an industrial scale with car tyres. Of course the rubber tyre has very different material properties to the plastics used in the shredder. Has anyone tried putting rubber into their shredder or has a shredder they would be willing to test it on? If anyone knows the torque value needed to shred the plastics this would also be helpful as I could compare this to shear strength values.