The lower hitch opening of the Stealth hitch that fits your 2009 BMW Z4 part # SH86VR will be very tight and stable once attached. It won't have any movement so it wouldn't add any additional movement or play to your bike rack setup. view full answer...
The full deflection range of the spindle on the Timbren Axle Less kit part # ASR2000S02 is 2-5/8 inch. Which also happens to be the same distance from the spindle center to the frame. That means when this is fully compressed it will be the same height as the frame channel.
The kit should be used with standard ST rated trailer tires. view full answer...