Vortex Racing has been manufacturing championship winning sprockets since 1995. Their race proven CNC machined aluminum sprockets are made from the highest strength 7075 aircraft grade aluminum and have become the industry standard for light weight, high strength sprockets.
Vortex rear sprockets are available in 7075 high strength aircraft grade aluminum and steel. Aluminum sprockets are lighter weight and preferred when performance counts. Read here about improving handling and horsepower by removing unsprung rotating mass from a motorcycle.
Eletro-plated black steel sprockets are more durable and will last longer if you are racking up the miles commuting to work.
Aluminum sprockets are available with type 2 anodize in black, blue, red, or natural aluminum. Vortex also offers their aluminum rear sprockets in F5 Hardcoat. The F5 PTFE Black Hardcoat is built for endurance. After type 3 hard anodizing with a jet black dye, they then coat the sprocket with PTFE (Teflon type material) for added lubricity. The result is an ultra tough, ultra light sprocket that stays cleaner and lasts longer.
Kawasaki Ninja 400 Info:
OEM Sprocket Size on the Kawasaki Ninja 400 is 14T front and 43T rear and the stock 520 chain is 106 links. Some sprocket combinations that work with the stock chain are:
13T Front / 41T Rear (Recommended for faster acceleration, some loss of top speed)
13T Front /42T Rear (Recommended for faster acceleration, some loss of top speed)
13T Front / 43T Rear
14T Front / 40T Rear
14T Front / 41T Rear (OEM Sizes)
14T Front / 42T Rear
15T Front / 40T Rear
15T Front / 41T Rear
Yamaha R3 Info:
The R3 OEM chain pitch is 520 and length is 112 links and the OEM sprocket sizes are 14 tooth in the front and 43 tooth in the rear.
A few different ratios that I have tested and all work with the stock chain length are:
13T front, 42T rear
13T front, 43T rear (Recommended for faster acceleration, some loss of top speed)
13T front, 44T rear (Recommended for faster acceleration, some loss of top speed)
14T front, 42T rear
14T front, 43T rear (OEM Sizes)
14T front, 44T rear
15T front, 43T rear