Roadrider compatability

Ask Avon, they respond very quickly, MKII's have not been out long enough for non Avon people to know.

https://www.avontyres.com/en-gb/contact/

No problem at all, you can check on their website. Both are just cross ply, it becomes an issue if it belted ply or radial. Do not confuse radial with radial ply. A motorcycle tyre marked radial is a totally different construction. 

To follow up on Ashley's post- you can run a radial rear with a bias ply [cross ply] front but never run a radial front with a bias ply rear.

Yes, but a Bias tyre is not a conventional cross ply. It has cross ply construction with additional cords. Do not mix them up. A tyre with B on it is Bias ply. There are plenty of compatibilty charts out there. Some show Bias some show Belted but the same applies.