Aim Variable Pressure Clutch
AIM Variable Pressure Clutch
CW EVALUATIONS
Easy squeezy for Harleys
CLUTCH HAND HURTIN’ FOR CERTAIN, Bunky? When you yank on your Harley’s clutch lever, does it feel like the other end of the cable is welded to the frame? If so, the AIM Variable Pressure Clutch for Harleys just may be the relief your carpal tunnel has been begging for.
Actually, the AIM is not an entire clutch; it’s a replacement pressure plate equipped with a number of barrel-shaped weights (6, 8 or 9, depending on the H-D model and engine size) that get swung outward by centrifugal force as the engine revs. The pressure plate is designed so that initially, it relaxes some of the force exerted on the clutch plates by the big diaphragm spring; that makes the clutch lever easier to squeeze when the engine is idling. As soon as the engine starts to rev, the weights fly outward, and little levers on the opposite end of their pivot arms push against the clutch pack, increasing the overall force exerted on the plates. The faster the engine spins, the greater the pressure on the plates.
We installed an AIM not on a stock H-D but instead on the 120-horsepower, 120-inch JIMS engine that we evaluated in our April, 2005, issue. We used the heavy-duty AIM model intended for up to 103-inch engines and supplemented it with one of H-D’s own Screamin’ Eagle high-performance clutch springs.
Even with that heavier spring, clutch pull was significantly lighter than that of a stock H-D Big Twin. We spent considerable time in stop-and-go traffic that demanded constant clutch use but never felt any of the wrist and forearm aching that usually accompanies that kind of riding on a Harley. Yet despite the amazingly light lever pull, hard launches, full-throttle upshifts and top-gear rollons begun at or near the engine’s 121foot-pound torque peak never resulted in any clutch slippage whatsoever.
Installation is easy, requiring only the removal of the derby cover on the primary case for access to the pressure plate. The units sell for between $225 and $245, depending upon the H-D application. Some also come with a stiffer spring, which ups the tariff to $300. Your wallet might squawk at the price, but your left hand will love the results. □
DETAILS
AIM Corporation
www.aim-tamachi.com
$225-300
