Unity 5 wheel collider issue (incredible force generated by suspension regardless of spring or damper values)

Our motorcycle is using 2 wheel colliders. Whenever the bike comes down hard on its back tire, the back tire is launched into the air (see the two videos below).

https://www.youtube.com/watch?v=gtu7pIQerks

I would expect this to happen if the rear wheel collider’s suspension had a high spring value, but this happens regardless of the suspension’s spring or spring damper values. We’ve tried combinations of spring and damper values from 5-500,000 and we get the same result regardless.

The only thing that seems to affect this crazy upward suspension force is the rpm of the rear wheel, but without a high rpm, the bikes couldn’t move quickly, so that doesn’t help much.

PLEASE HELP ME!!! THIS WASN’T AN ISSUE IN UNITY 4!!!

So I came up with a “solution” for this. I placed a small sphere INSIDE the wheel collider so when the wheel collider slams into the ground (somehow) the sphere ends up colliding first and there’s no bounce. If this doesn’t work for you at first, try repositioning the sphere until it does.

I have similar issues with u 5. I ran across a forums topic, that indicates this is a bug in unity 5.
really wish I could be more help.

check this video to solve problem of wheel collider bouncing on unity5