JP Timing Sprockets and Gears are made from Billet Steel for all Performance requirements.

JP Timing Sprockets and Gears are machined on CNC lathes.

Billet steel blanks are cut from six metre lengths of steel which are then machined using CNC lathes to form the required part. These are carried out in two operations; the first operation involves boring the hole (so it will fit on the crankshaft or camshaft) and the chain groove; the second operation finishes the part off after it has been turned around in the lathe.

Hobbing cuts the sprocket teeth.

The parts from the lathes must have the teeth or gears cut in them. This process is called hobbing for sprockets and straight cut gears or gear cutting (generation) for helical gears. This process is the longest in the manufacture of sprockets and gears as it cannot be rushed.

After the sprockets have been hobbed they will be linished to remove any burrs. For gears they are shaved, this process involves a small amount of material being removed if necessary to ensure that the gears mesh at exactly 90 degrees to each other. If this angle is out by even a second it will wear the gears prematurely or break.

Induction Hardening.

The final manufacturing process for crank sprockets and gears is to induction harden the teeth. This process involves using electricity to heat the outside of the sprocket or gear to 1000 degrees Celsius and then quench it instantly in water. Induction hardening is used to pre-work harden the sprockets and gears so they will not wear as rapidly as un hardened sprockets. This means that the sprocket will last longer and save on chain wear. For more information on hardening follow this link.