Works Performance Inc. custom-manufactures shock absorbers for off-highway vehicles, motorcycles, and bicycles. The Northridge, Calif. firm originally used no bearings at all in the shafts of its shock absorbers, instead using a lubricant to let the parts move easily, and seals to maintain cleanliness and integrity. “We ran hardchrome steel directly against aluminum,” said Gil Vaillancourt, president of Works Performance. “This required lubrication for both the seals and the bearing surfaces.” (Dry coefficient of friction for aluminum on steel can be about 0.5.)
Works Performance began using Iglide G300 bearings to reduce friction in the 1/2-in.-diameter shafts of the shock absorbers and lengthen the useful life of the shock. Against steel without lubrication, these bearings have a dynamic coefficient of friction between 0.09 and 0.20.
“Switching to the bearings in the seal holders produced significantly smoother operation, while virtually eliminating wear,” Vaillancourt said. “We still pack lubricant for the seals, but the bearing does not require it, so we can essentially forget about it.”
Because the bearings worked so well in the linear application, Works Performance decided to test them in the mounting bushings in the eyes and bodies of the heavily loaded ATV racing shock absorbers. The nature of the application here is oscillatory rotation, with heavy pounding loads. Due to the harsh nature of the application, Works Performance had been using expensive and not-so-readily-available spherical ball bearings. The switch to thermoplastic plain bearings was cost effective.
