It is important to have the correct gear ratio for the tire size for proper operation of your clutch or torque converter.A improper gear ratio make the clutch or belt slip and cause damage to the unit very quickly.To determine the gear ratio necessary for your go kart or mini bike you must know the limit of your top speed.When using a clutch to drive your go kart the top speed on flat terrain is 35mph, if the terrain is hilly or the weight of the driver is high the top speed should be 25mph.Mini bikes work best with a top speed of 25mph for .When using a torque converter with a go kart you may go as high as 45mph on flat terrain and 35mph on hilly terrain.For mini bikes 35mph is the top speed when using a torque converter.Fitment Type: Direct ReplacementFitment:for Primarily Mini Bikes Go Kart Parts(for reference only)Colour:As ShownMaterial:MetalPackage Contents:1 x Centrifugal ClutchOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.