Having studied with interest Mick Payne’s article ‘Rubber Side Down’ in the May 2019 OBM I’d just like to add my £2.20 pence worth.
Obviously, as you indicate, the practice of fitting car tyres to motorcycle rims is a practice that, in theory and due to difference in rim design, gives cause for concern and is not recommended by yourselves and serious consideration should be given to undertaking this, and I agree.
Now, and speaking from experience, this is something I’ve done on four occasions without problem other than actually selecting and getting the chosen car tyre on to the rim, and this is something I definitely would not do (or recommend that anyone else does) on a spoked wheel.
But, as most modern motorcycles run aluminium wheels designed for tubeless tyres, I, and many other sidecar pilots, have found that 16-inch bike rims are very close in design to car rims with 17-inch bike rims (although I’ve not measured) seeming to be a few millimetres larger in diameter, given the effort I applied to get a car tyre on a 17-inch bike rim.
So far I’ve not had the need to try and remove a car tyre from a bike rim but I suspect that will prove even more difficult than actually seating the car tyre on the bike rim in the first place, but I obviously feel gains in both tyre wear and stability are well worth the effort.
Read more in the June 2019 issue of OBM – on sale now!