I was wondering what size is most common. I have a 320mm which I find a touch too big and would prefer summat like a 280-300 but I guess that would mean having to really be on top of the thing when turning and perhaps the smaller ones are not that suitable to road use.
What are peoples thoughts?

I think about 12 - 13 inches (300 - 330 mm) is about the norm (NOT my 16" )

We have a 300 wheel that has flat tops and bottom so only 260 top to bottom.
This seems to work out fine for our road car and clears the knees easily
Richard

I had a 280 which I changed to 320 which felt much better.Smaller wheel felt twitchy at higher speeds heavier steering at low speeds cheers Keith

Aye that's my concern that it may be twitchy. I think I'll stay with the big un then. Ta.

I just fitted a 12" wheel in place of the original Sierra wheel and what an improvement - just weights up the steering a bit and so much better to drive.
John.