This picture is a shot of the Bader Model BM2 bench grinder that has been retrofitted with the spring kit I make. The spring sits in the same position as the regular coil spring that came with the machine, but provides considerably more tension, and thus helps to improve the machines tracking ability. The only modification required to fit it to the machine is cutting the pin that the coil spring used to sit on down to 1/2" long. The spring is austempered L-6 tool steel, individually forged to a taper, heat treated under precise conditions, and guaranteed to last. It really is an improvement, and one that I only recently was talked into making available as a regular item.
Shipping paid, the kit costs $45. It will be delivered UPS ground, unless you are out of the United States, then it will go Postal System, and the cost will be different.
Photo courtesy of Don Fogg and his digital camera. (This is his grinder too, but I did make the spring kit.)