WHAT IS IT? The Hinson Single Spring (SS) clutch is exactly what it says it is?a 2009-2011-2012 Honda CRF450 clutch that uses one spring.
WHAT’S IT COST? $599.99 (inner hub, pressure plate and Belleville spring), $99.99 (Hinson clutch plates), $159.99 (Hinson clutch cover).
CONTACT? www.hinsonracing.com or (909) 946-2942.
WHAT STANDS OUT? Here’s a list of things that stand out with the Hinson SS CRF450 clutch.
(1) The problem. The four-spring clutch on the 2009-2012 Honda CRF450 is wholly inadequate for the job. The four springs do not provide enough pressure on the clutch pack to stop it from slipping. The slipping creates heat, which causes the plates to swell. The swelling introduces plate-to-plate drag, and the end result is that halfway through a hard moto the clutch won’t disengage, and after that it won’t engage. Not a pretty picture.
(2) The solution. If six springs are better than four, then how can one spring be up to the task? That’s easy. Hinson uses a special oversized cupped washer as a spring. Called a Belleville washer, it distributes the load evenly around its circumference. As a result, it can stand up to substantial loads and is highly useful in areas subject to thermal expansion, vibration and high-bolt loads?all of which describe a motorcycle clutch. KTM has developed a Belleville-style clutch for the 2012 450SXF.
(3) Installation. The $599.99 Hinson SS clutch kit consists of a Belleville washer-equipped inner hub and a special pressure plate. To install it, you swap out the stock pressure plate and inner hub for Hinson’s SS components. The job takes about 20 minutes.
(4) Performance. The spring pressure on the stock four-spring CRF450 clutch is approximately 275 psi. The Hinson SS clutch ups that to 300 psi. The extra bite of the stiffer Belleville washer is enough to extend the life span of the stock CRF450 plates immensely. Most MXA test riders can’t keep the stock CRF450 clutch alive for more than four motos; with the SS clutch, we could go for months.
(5) Feel. In back-to-back tests, the Hinson SS clutch delivered an accurate, hooked-up feel that was in stark contrast to the sloppy, vague feel of the stock Honda clutch. It should be noted that the engagement zone of the SS clutch was very precise. Even though it releases over a small range of movement, that movement is far enough out on the lever travel that you don’t have to pull the clutch all the way in to guarantee disengagement (which is common on the stocker). The pull of the Hinson SS clutch is firm because of the stiffer spring rate, but once test riders pulled the clutch through the firm spot, it got easier in the second half of travel.
WHAT’S THE SQUAWK? MXA had two complaints: (1) Although Hinson isn’t to blame for the shortcomings of Honda’s actuation lever arm, it hinders both the stock and SS clutches alike. (2) The price is fair for Hinson’s billet T-6, akadized aluminum parts, but the price comes on top of the initial $8250 investment.
We’d give it five stars if the operating window was a little broader. As is, it works much better than stock. You gotta go forward to win…and you can’t do that with a clutch that slips.