It would also be interesting to compare rim width...
My Plus 8/Aero S4 Chassis has 225 front, 245 at the rear, both on 8.5" rims.
What is the rim width on the S1?
On the S4 the rim width is the same, front and back and is correct for 245 tyres but at the front the 225 is the narrowest possible tyre allows on the rim, with the result that the wheel rim is the widest point... Ideally the front wheels would be 7.5" wide, not the 8.5" used.
I'm no expert, but it does seem to me that for road use fitting optimal tyre/wheel combination will lead to a better ride and grip.
