If there was an undetectable cheat code for smoother, faster riding with less fatigue, we’d all jump on it like a pack of Nintendo nerds with the latest Game Genie. Well there is something along those lines. Most riders have heard of the auto clutch concept, but the Rekluse z-Start Pro
is one that combines traditional clutch action with an automatic twist.
We threw our 2008 YZ250F down on the floor and went to town installing the Rekluse z-Start Pro. The instructions made everything very simple.
The system is made from billet 6061-T6 aluminum and billet 4140 steel and replaces your stock clutch with a completely different lower and upper assembly with hard anodized center clutch and pressure plate. The pressure plate is controlled by centrifugal force and engine rpm and operated by 30 steel bearings on a ball-ramp plate and a corresponding spring. The engagement point and how hard it grabs are adjustable by changing the spring or adding/removing the number of ball bearings.
Unlike other Rekluse models, the Pro model incorporates a manual override which can be used at any point in the rpm range. That means full-on motocross starts or an extra blip to lighten or control the front end is now possible. However, the feel at the lever is much different than stock with a pull that is lighter than hydraulic units. It takes some getting used to, but soon you’ll be fanning the clutch with the same accuracy as before… If you want to that is. It’s possible to ride entirely without the override, but Rekluse makes other models if you have no love for the left lever. When the clutch warms up and requires adjustment, it can be done just like a stock unit. It isn’t as immediately responsive to free-play adjustments as a standard cable clutch, but it only takes a few extra seconds to get things right.
The stock clutch fiber plates are retained, but virtually everything else is replaced.
Installation on our 2008 YZ250F was straightforward. Anyone who can follow directions and has the proper tools will be able to walk through the process with little trouble. Right away the auto clutch was phenomenal. It was surprising how quickly we stopped reaching for the lever when stopping or shifting. After riding hard and pounding mercilessly through the gears we never had any issues with missed shifts or even difficult cog changes. Hillclimbs were one particular arena where it was good to have the override option, and it also pointed out the only two issues with the Rekluse. Both were pointed out during failed climb attempts. Stopping mid-hill is difficult because the bike freewheels backwards without the engine acting as a brake. This is easily avoided by simply planning ahead and getting turned sideways before losing all momentum. Secondly, we usually bump start the motor on the way down but the Rekluse doesn’t allow for this. Not being able to bump start made us realize how often we use that technique, and it was annoying at times. Fortunately we rarely have to do it because it’s almost impossible to stall the motor unintentionally.
These ball bearings are the hidden magic and are activated by centrifugal force.
The applications for the z-Start are endless. We put it on our YZ250F motocross bike and used it to help reign in the snappy power and aggressive delivery for enduro use. Yamaha’s 250F isn’t really that burly, but we expect that the Rekluse would be even more impressive on a big bike. Many of the top off-road race teams use motocrossers as the platform for their race bikes. Our experience with riding 450 MXers on the trails has always resulted in a tired and sore left arm. Clutching those bad boys gives the hand a workout, which is probably why riders like WORCS champion Nathan Woods and off-road legend Ty Davis have run Rekluse products. If you make it to an EnduroCross event this year, watch how many riders are sporting the spider logo.
We’ve been riding with the z-Start Pro for a few months now and we’re still learning how to ride it better and getting faster. The drawbacks are so minimal that they are far outweighed by the gains, especially if you plan on sticking to the motocross or GP tracks. Plain and simple, we like riding our YZ-F better with the Rekluse installed, and anything that makes us want to ride more is a winner in our book. The auto clutch really is like cheating, and we love it, yet it still allows all the benefits of manual action. There’s no reason not to have one.
For more information about the Rekluse z-Start Pro
, visit their website.