Insurance

[Lawrence]

Lawrence, I think your missing the point there. You may choose to have it to avoid being out of pocket if some cnut did crash into you but the liability would be with them anyway. If Insurance wasn't a legal requirement we may see a reduction in costs but unlikely.

That's true, but you'd still be the one with a written off bike and no way of getting it fixed apart from using your own insurance or paying out of your own pocket until you manage to sue the other person

I agree with your last point through, very unlikely costs would actually go down.  I'd image they'd go up to cover less policies being taken out.