Changing tyres sizes - tyre size change calculator

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Changing Tyres Sizes - Tyre Size Change Calculator

When considering changing wheel and tyre sizes, it is necessary to maintain a diameter that is as close as possible to the original so that the gearing of the drive train is not adversely impacted.  Doing so will also ensure that the ride height will not change significantly.

Old »
Tyre »
Size »		 Tread
Width		 Profile
Height		 Wheel
Diameter		 Overall
Tyre Diameter
  mm   %   inches   inches
mm
Do not select impossible tyre sizes ; Check manufacturers.
New »
Tyre »
Size »		   mm   %   inches   inches   mm
We recommend a MAXIMUM of +/- 2.5% difference
Difference  in  Diameter  =  %    
Actual diameter change =  mm