Below are a couple of graphics demonstrating the effect of rear overhang on axle weights if a couple of bikes are stored on the rear bike rack. The results are similar to towing a 500kg trailer with 10% of the towed mass applied vertically on the tow ball.
It is clear that a significantly higher weight than the actual 50kg applied load is added to the rear axle weight, 85kg for the vehicle with the longer rear overhang. The vehicle with the smaller rear overhang is 15kg better, with 70kg added to the rear axle weight.
This demonstrates that if you are near or over your rear axle weight, you need to be careful adding extra weight at a distance from the rear axle as it rapidly increases the rear axle weight.
Do you know your actual axle weights?
If you would like to try some estimates for your vehicle, the calculator below will do the calculation for you. If you discover either your axle weights or vehicle mass is exceeding your registered GVM check to see if your vehicle could be Re-rated to higher weights in the Vehicles menu above. Or contact LoadSafe. Not sure of your registered GVM, try www.carjam.co.nz.