Do I have to roll arches for 225s nb8b?

[MattR]

Generally the tyre width shown in the size on the sidewall is the nominal tread face width and not the actual width of the tyre in the sidewall that you would expect.

I have run 240 nominal width slicks that were narrower in the sidewall than 235 wide road tyres, however the tread widths were as expected.

About the only way to make sure of the widths is to get the tyre size charts from the manufacturer's and compare the actual sizes. Also note that the actual sizes measured on the car will also change if you fit the tyres to rims that differ from the rim width nominated in the spec sheets.

[mazmad]

Thanks.