REKLUSE Z-Start Clutches

What is it?

The z-Start Clutch is a retrofit automatic clutch. It works using centrifugal force to automatically and smoothly engage the clutch just by using the throttle. The z-Start manages the clutch function so the rider can focus on riding and having more fun.

What is included with the z-Start Clutch?
The main portion of the z-Start is the clutch assembly. The clutch assembly consists of a lower assembly that bolts directly to the bike’s center clutch. The ball-ramp pressure plate with balls and a top plate then mounts to the lower assembly.  The z-Start Clutch includes a throw-out assembly to allow the auto-clutch to be disengaged.  There also a set of steel drive plates to enable adjustment of the clutch pack height. There is usually a thicker gasket to provide some additional clearance for the z-Start. Everything except basic tools and two sets of feeler gauges are provided in the kit to complete the installation.

What is the z-Start made from?
The z-Start Clutch is made from the highest quality billet 6061-T6 aluminum and billet 4140 steel, precision CNC machined to tolerances of .001" (that's one one-thousandth of an inch).

How does it work?

The z-Start Clutch is a centrifugal clutch that uses ball bearings to engage the clutch.  The clutch provides a pressure plate with ball ramps. At idle the balls are at the bottom of the ramps and the pressure plate is disengaged.  As the rider increases RPM, the balls move out the ramps, push on the Rekluse top plate and force the pressure plate into the clutch pack engaging the clutch. As RPM’s build, the balls continue to move out fully engaging the clutch.  When engine RPM’s are reduced the balls drop back down the ramps and the clutch disengages. The take-off is smooth--as if you had perfectly feathered the clutch every time.  The disengagement is quick eliminating any stalls. 

At what RPM does the z-Start Clutch engage?
The z-Start is fully adjustable so the rider can set the RPM engagement point.  Springs are used to provide back pressure to the clutch and disengage it at idle. It takes a certain amount of force to overcome the spring and engage the clutch. By changing springs and spring compression rates, the rider can easily set the RPM engagement point.

For example, a light spring can be easily overcome at a low RPM so the balls generate enough force to compress the spring and engage the clutch. This provides a hard engagement at a low RPM which is ideal for enduro riding. A heavy spring requires more force to compress so it takes higher RPM to compress the spring and engage the clutch. This provides a soft engagement with some clutch slip which is ideal for track riding, allowing riders to brake slide into corners and accelerate out of them faster with better traction control.

Does the z-Start require me to modify my existing clutch parts?
No. The z-Start Clutch simply replaces your stock pressure plate. No need to take apart the right side of your engine to get the whole clutch out. No need to send your parts away for permanent modification or to modify your existing clutch parts. With the Rekluse z-Start Clutch, you can always return any bike to a stock configuration.

Can the clutch lever still be used?
The z-Start Clutch is provided in a fully automatic mode. The z-Start Clutch on cable clutch bikes can be operated in a semi-automatic mode by adding the Rekluse Perch Adjuster. With the Rekluse Perch Adjuster, the clutch lever can be retained to override the auto-clutch just like the stock clutch lever does.

Hydraulic clutch bikes, like a KTM, do not need to add a Rekluse Perch Adjuster and can be configured in either fully automatic or semi-automatic mode.

What is the Rekluse Perch Adjuster?
The Rekluse Perch Adjuster is a device which mounts inline with the clutch cable and mounts into the stock clutch perch. The Rekluse Perch Adjuster provides two main benefits. Installing the Rekluse Perch Adjuster allows the rider to retain the clutch lever and provides the ability to override the z-Start Clutch. Additionally, the Rekluse Perch Adjuster allows the rider to adjust the engagement point of the z-Start Clutch.  Two spring options are provided to allow for different engagement points. The Rekluse Perch Adjuster is also threaded to allow additional spring compression and therefore further engagement adjustment.

How difficult is the z-Start Clutch to install?
Riders who regularly perform maintenance on their clutch components can easily install a z-Start Clutch. Most people will spend 1 to 2 hours to read through the manual completely and carefully install the z-Start. After the first installation, subsequent installations after can be completed in 30 minutes to an hour.

Does the z-Start Clutch require me to modify my existing clutch parts?
No. The z-Start Clutch simply replaces your stock pressure plate. No need to take apart the right side of your engine to get the whole clutch out. No need to send your parts away for permanent modification or to modify your existing clutch parts. Rekluse always provides the ability to return any bike to a stock configuration.

Will the z-Start Clutch wear my clutch plates faster?
That depends on how you use or abuse the z-Start Clutch. With the z-Start Clutch, you will find that you are able to ride smoothly in one or even two gears higher than you normally ride. However, riding uphill, in 4th gear at 10mph for extended period of times will cause significant clutch slipping, accelerate clutch plate wear and possibly damage your engine. When riding with any automatic clutch, it is important to select the right gear for the situation. In general, it is safe to ride one gear higher than the riding conditions dictate for short periods of time. That being said, when used properly the z-Start Clutch should allow for clutch plate life equal to or better than a stock clutch.

What kind of maintenance does the z-Start Clutch require?
The z-Start Clutch is designed to work with a specific ‘installed gap”.  The installed gap is the distance between the pressure plate and clutch pack when the bike is off. The installed gap is based on the distance that the balls rise in the ball ramps as the pressure plate is engaged.  If the installed gap is too small, the pressure plate is too close and will cause the bike to drag at idle. If the installed gap is too large, the pressure plate cannot fully clamp the clutch pack and the clutch will slip excessively.

In order for proper operation and to maintain the life of the clutch pack, the installed gap must be kept in the prescribed range. Initially, the installed gap must be checked after breaking in the z-Start Clutch for twenty minutes. As clutch wear occurs, the installed gap needs to be checked at regular intervals. Rekluse ends riders check the installed gap after every 25 hours of riding.

How much weight does the z-Start Clutch add to my bike?
Installing the z-Start Clutch adds less than 6 ounces of rotating mass in the clutch. Keep in mind that the clutch spins at approximately 1/3 engine speed so flywheel effect of the z-Start is minimal.

Is it for me?

I'm new to dirt bike riding. How can the z-Start Clutch help me?
Riding with the z-Start Clutch removes the frustrations of clutch control and stalling that many new riders face. Working the clutch smoothly, especially at lower speeds or on hills is challenging for experienced riders. The z-Start Clutch manages the clutch operation perfectly so you can just focus on the fun of the ride!

I'm a pro-level motocross & supermoto racer. How can the z-Start Clutch help me?
With proper tuning of the z-Start Clutch for track conditions, most riders will be consistently faster off the starting line with a "roll-on" start than by "feathering" the clutch off the line. The z-Start Clutch allows the rider to forget about the clutch lever for most racing situations and focus on the track in front of the rider. Without the need to reach for the clutch lever during braking, over jumps and out of corners, fatigue is greatly reduced and control is improved. With a high engagement point, corner exit speed is typically better because the z-Start "feathers" the clutch perfectly every time. The z-Start is virtually stall-proof and even after a crash, most bikes can be picked up and ridden away quickly without fear of stalling.

I race cross-country events. How can the z-Start Clutch help me?
In technical trail sections, the z-Start Clutch really shines. Forget about the using the clutch lever to negotiate slow, technical sections and focus completely on the trail in front of you without fear of stalling and precise control of speed and power to the ground. For technical hill climbing, the z-Start Clutch allows you to back off the throttle to negotiate obstacles and then reaccelerate without fear of stalling the engine or "looping-out". Most riders can attack corners more aggressively by brake sliding into the corner and then accelerating without the need for delicate clutch work or a gear shift; reducing physical and mental fatigue on the rider. The z-Start Clutch is virtually stall proof and even after a crash, most bikes can be picked up and ridden away quickly without fear of stalling.

I'm an experienced trail rider. How can the z-Start help me?
Riding with the z-Start Clutch makes every ride more enjoyable. Without the need to manipulate the clutch lever, the rider has less fatigue and the bike is considerably more forgiving in almost all situations.  The z-Start Clutch can reduce the stress and anxiety of traversing technical sections of trail or difficult hill climbs. The z-Start Clutch adds trials-bike like control to motocross bikes and trail bikes alike; allowing the rider to take a whole new approach to sections of trail most riders struggle through.

What if I have problems?

What kind of warranty does the z-Start come with?
The z-Start Clutch is backed by a 1-year warranty from defects in material or workmanship on all Rekluse manufactured parts. The z-Start Clutch also includes a 30-day money back guarantee. If for any reason you are unhappy with how the z-Start Clutch performs in the first 30 days of use, simply contact Rekluse or our dealer for a return authorization and we will gladly refund your purchase.


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