The returned-from-the-dead six-spring clutch.
Have you ever wished that you could get your hands on an unobtainable
works part from the factory? Be careful what you wish for. Every 2009 through 2012 CRF450 came with a Honda works part—the four-spring clutch.
The works clutch is a trimmed-down, lightened-up, minimalist design that
lessens rotating mass and inertial forces on the working parts of the
clutch. The key difference between Honda’s works clutch and all previous
clutches is that Honda’s engineers saved weight by lessening the number
of springs in the unit.
Back in 2009, Honda’s engineers considered the four-spring clutch a
marketing coup because it was a direct transfer of technology from the
factory race bikes to the production bikes. Sadly, without a factory mechanic to change the plates (between motos) — the trick titanium clutch springs and the billet-machined parts of Team Honda’s inner hubs and baskets—the four-spring clutch proved less than ideal in the hands of local racers. Why? To duplicate the clamping pressure that the clutch pack needed with four springs instead of six, they had to increase the pull.
Honda had to compromise by sacrificing clamping pressure (the 2009–2012 Honda clutch has about 35 pounds less clamping pressure, plate to plate, than the 2008 clutch). The result was a clutch that couldn’t hold up to any abuse—or it would slip. What is the fix? MXA has four Honda CRF450 clutch strategies—from cheap to expensive. Pick your poison.
Honda's four-spring clutch made Hinson richer and CRF450 owners poorer.
SOLUTION #1: DON’T USE IT
The easiest fix for the CRF450 clutch is to just not use it. It will last forever if you never slip it.
SOLUTION #2: THROW PARTS AWAY
When the 2009 CRF450 clutch proved troublesome, Honda redesigned the clutch-plate arrangement by removing one full-size friction plate and replacing it with a skinny plate and two Belleville-style washers (called jutter springs). The idea was to put back pressure on the clutch pack. This didn’t solve the problem, and might have aggravated it. MXA removes the small clutch plate and two jutter springs and puts one full-size clutch plate back into the pack. This returns the 2010, 2011 and 2012 CRF450 clutches back to 2009 specs. It is an improvement, but not a solution. This mod costs $8 (for one additional clutch plate).
SOLUTION #3: THE OLD-SCHOOL METHOD
The next fix is old-school. We simply replaced the stock clutch springs with specially wound Hinson, Barnett or Pro Circuit clutch springs. They are stiffer, and the coils are wound to provide the most progressive modulation possible. Exchanging the four stock springs for four stiffer springs increase the clamping pressure to where it should be to replicate the 2008 clamping pressure. But, stiffer clutch springs mean a significant increase in clutch pull. Plus, the actuation point of the CRF450 clutch, which is too quick to begin with, becomes quicker with stiffer springs. This is a fix that increases hook-up and plate life significantly, but makes the window of usage very small. This mod costs $49.95.
The four-spring (left) and six-spring clutch (right) are night-and-day different–well, two-springs different anyway.
SOLUTION #4: PONY UP FOR SIX
The ultimate CRF450 solution is to install an aftermarket six-spring clutch. It requires a new pressure plate, inner hub and six springs (you can use the stock 2009-2012 CRF450 basket). This turns the four-spring clutch into an exact replica of the 2008 Honda CRF450 six-spring clutch. This mod costs over $600.00.
There you have it. The choice is yours, and you control your fate with your left hand. Use it with caution.