Insert your existing wheel and tyre specs, and the desired size, and the outcome is shown on the diagram.

Your existing setup

Existing Tyre
Existing Wheel

Your new setup

New Tyre
New Wheel
Your Results

Existing

New

Diameter
659.7mm
654mm
Circumference
2072.5mm
2054.6mm
Poke
61.6mm
38.9mm
Inset
141.6mm
138.9mm
Speedo error
0%
0.87%
Reading at 30mph
30mph
30.26mph
Reading at 60mph
60mph
60.52mph
Ride height gain
0mm
-2.85mm
Arch gap loss
0mm
-2.85mm
Wheel Fitment Guide

Compared to your existing wheel, this new wheel will have an inner rim which is 2.7mm further away from the suspension strut. The outer rim will poke out 22.7mm less than before.

The strut shown in the diagram is for show only. Don't worry if the wheel looks like it fouls!

Bear in mind most tyre manufacturers vary slighty from the specs, and that it could be dangerous to run tyres on wheels they aren't designed to fit.