Parameters
It’s technically fairly straightforward but mounting design is important as the loading varies from that of a standard towbar, most cars being rated to 75 kg down-force and heavy duty models on the campervan to 150 kg. A typical 50 cc scooter is around 85 kg and most trail bikes or larger scooters will be more. You have to add the weight of the carrier to this.
Some commercial carriers overseas fit into the hollow receiver hitch where the removable-tongue towbar sits. I was concerned about this loading, the stability and vibration. Only a single bar fixes this carrier to the vehicle and the scooter is loaded off-centre. It also means that the towbar isn’t available during this function.

Solution
For me, the vehicle chassis had to be strong enough to take a load further out than a towbar where forces acting on the chassis and bolts are higher. Do not stint on the mountings—if in doubt, get a towbar company to make the mountings and chassis modifications.
I ordered a towbar installed and since the campervan has a Certificate of Fitness (CoF), it needed to be a certified one. At the same time, I had the sockets made for the scooter carrier to slot in so that everything would fit together.

Read more in the June/July 2010 issue of The Shed