JS Motorsports’ forged med C.R. pistons for 750cc Nortons weigh approx 185 grams forged or 175 grams billet, compared to 250 grams for a stock Commando piston. 850 pistons weigh approx 210 grams forged or 185 billet compared to 317 for a stock piston. High strength .708″ pins will save about 18 grams each compared to stock pins. Our Longer, lighter Carrillo rods will save about 30 grams each on the small end compared to standard Norton steel Carrillo rods because there is no need for a bushing when using the DLC coated pins (the small end is what shakes your bike), Our rod small ends are also approx 30 grams lighter than the aftermarket aluminum rods which have been known to fail. Big end weight is similar to the standard length bushed Carrillo rod and the stock Norton rod.
These important weight savings reduce vibration and stress within the motor, thus a reduction of the shaking forces by approx 1/3 with JS Motorsports’ rods and pistons, and that means 1/3 LESS VIBRATION.Translation = Smoother ride. The reduction of shaking forces and related stresses help to save your cases, crank and everything else from failing, and that can save you lots of money.
Piston, lifters & valve spring weight comparisons
| JS lightweight bare pistons med C.R. | 750cc = 185 g forged or 175 g billet | 850cc = 205 g forged or 185g billet | |
| Stock Hepolite bare pistons | 750cc = 250 g | 850cc = 317 g | |
| JS bushless Carrillo rods | small end 105 g | big end 326 g | |
| JS bushless Ultralight Carrillo rods | small end 95 g | big end 307 g | |
| JS DLC pin | 750cc = 51 g | 850cc = 58 g | |
| Stock pin | 750cc = 68 g | 850cc = 72 g | |
| JS Beehive valve spring | 42.3 g | TI retainer 4.7 g | Street seat pressure 90 lbs Race seat pressure 130 lbs |
| RD racing spring | 59.3 g | TI retainer 10.8 g | Race seat pressure 130 lbs |
| Stock spring | 59.7 g | steel retainer 16.1 g | Street seat pressure 90 lbs balanced with shims. 100+ lbs shimmed for racing |
| JS (BSA) radiused lifter | 38 g | ||
| Stock flat lifter | 74.6 g | ||
| JS pushrod | 31 g | ||
| Stock pushrod | 32 g |
