Transmission Undercutting

As a lot of the current racers and a few of the new racers know that the little bikes do have issues with their transmission popping out of gear, these motorcycles are built as a commuter low budget bike that we, you want to take to the next level.

Spears Racing has been doing undercut transmissions for decades and has decided to specialize in the Kawasaki Ninja EX400,Ninja EX300,Suzuki SV650,MT07 and Yamaha R-3 transmissions with what we call the “Race Cut” this is essentially our way of doing the process of Transmission Undercutting( in the engagement direction only)

Once the undercutting process has been achieved, we then begin to work within the particular application to complete by blasting all of the transmission gears to maximize the surface area for cleanliness and inspect that the gears spacers,(shim if needed) washers are ready to assemble back onto the shafts.

Micro Polishing is  a procedure that all of the gears and the shafts are tumbled in a synthetic solution with special Media we have found to be the best finish, this procedure will remove the roughness peaks are removed, reducing the roughness profile height, therefore, this method increases the contact bearing area of the gear flanks Reduce Friction, Increase Efficiency Increase Effective Horsepower, Increase Power Density, Lower Operating Temperature, Extend Component Life, Increase Part Durability.

Undercutting is one of the most highly regarded modifications for race motorcycles. Many manufacturers do not undercut their transmissions at the factory. Undercutting involves the modification of the drive dogs and slotting to precise angles. Creating an interlock of the gears under acceleration, virtually eliminating the occurrence of an involuntary gear jump. Most drive dogs from the factory posses a Zero degree back cut, producing rounded gear corners under normal wear, in turn creating involuntary disengagement. Spears Racing’s under-cutting service can precision cut your transmission to perform at its most accurate and true level of performance.

***Exchange Service Available***