TUNING A REKLUSE CLUTCH

The Rekluse Auto Clutch technology and parts have made strides in auto-clutch and anti-stall clutch activation over the past decade. It has gone from a crutch to help riders who did not have clutch control to a highly tunable performance advantage for all levels of riders. I have been a fan of the clutch since the Z-Start days and continue to use them in many of my personal bikes. Especially my trail riding machines, but I’ve also used them in motocross bikes as well.

There are some very basic tips that can really help and simplify making the clutch work the best for you. Lately, we have been testing the EXP 3.0 and Core EXP 3.0, Radius X and CX, and thought we would offer these tips to help Rekluse owners get the most out of their tool. One of the best features of the Rekluse EXP 3.0 Disc is that it is highly tunable so why not take advantage of that. You can make your clutch work how you would like it to.

With tuning, you can add hit or snap to the power delivery or even smooth it out. You can adjust the feel of compression braking on four-strokes as well as make the bike nearly impossible to stall. These are done through simple spring changes or by switching out to different weight wedges inside the EXP disc. And never underestimate how your idle RPM can factor into all of this. All of these tips assume the clutch is in specification with un-warped plates that have the correct clutch pack thickness. Also make sure the basket, bearings, and clutch dampers are all working properly or are fresh. Any slack or friction causing issues will compromise the performance of the clutch.

Free play gain is very important. It is the “pulling in” of the clutch (gap) that the EXP disc expands out into to make the bike go. Too much free play and the clutch will always slip. Too little and the clutch will drag. Setting it is critical and very well explained in the Rekluse manual. On hydraulic clutches, the free play gain is very simply adjusted through the clutch slave unit. On cable clutches, there is an adjuster built into the clutch pressure plate or it is done at the lever depending on the setup you have.

The most important thing is to have the free play gain set so that when you rev the bike in neutral there becomes free play in the lever (or you feel it move). The manual is very specific in how to tell if it is set correctly and how to fix it if it isn’t. If there is too little or too much free play, anything you do is a moot point. Ultimately,

you will wear out the clutch plates or the clutch will not work if free play isn’t set correctly. Take the time to set and understand the free play gain. I like to set mine so the lever moves at least 1/8th inch as recommended, but also know that there is some very high-level fine tuning available here for those that need it. Rekluse does not recommend this, BTW.

There are two easy ways to alter the feel and the way the clutch bites on the EXP. With spring changes and with different weight wedges (it was through a different number of balls and different weight balls in the Z start). The simple way is to isolate the change each individual part makes–springs change mostly the RPM where the clutch engages and the weights control mostly the “bite” the clutch has when it engages. There is some overlap, but for the most part, think of them individually. You can also simply play with the idle speed to change some characteristics of the clutch action.

The springs keep the EXP plate compressed. Lighter springs allow it to open sooner, heavier springs keep it closed (disengaged) longer.

Going to lighter springs allows the clutch to engage at a lower RPM. Heavier springs hold the EXP clutch together longer and have it engaging at a higher RPM. Mixing the springs (different colors=different rates) can yield half-steps. The recommended Rekluse setting is, for me, too high of a clutch RPM for most

The Rekluse is a very simple design for how complex its results are. It comes apart for tuning in seconds with just a screwdriver. Spring rates change with different color springs.

off-road riding. Lighter springs also allow the clutch to stay engaged longer, and if set properly, will not allow the bike to barely freewheel at all. In fact, I have mine set to drag slightly at idle, enough that I usually need to hold the brake lightly to keep from creeping forward. If you want a sharper hit or bigger power when the clutch engages, then stiffer springs are the way to go. It requires a slightly higher RPM for the clutch to engage and more RPM equals higher power. That will also let the bike freewheel easier if the rear wheel is locked and the RPM is not brought back up to re-engage the clutch. For fine tuning, raising or lowering the idle can really help the setting.

The wedge opens and closes the EXP plate. The more mass the weight has, the harder it is to get it to move. And when it does, it has more force. Here, RPM equals rotation equals force.

The weights change mostly how quick the clutch bites and how long it stays engaged on deceleration, then how quickly it lets go. The heavier the wedges, the harder the clutch bites (less progressive engagement) and the longer it stays connected. Lighter wedges slip a little longer and have a softer grab. I generally prefer the heaviest wedges (and sometimes would like heavier ones than are offered for some bikes) for off-road riding on most bikes that have decent power. Sometimes a small-bore bike (125s, 200s, 250Fs) can get bogged down if the wedges bite too hard. We have found that for most riders, the standard wedges are the

ideal setup.

To add an aggressive, more motocross-style hit to the clutch, adding a heavier spring setting and using heavy wedges will give the impression of a very quick and aggressive release of the clutch. This can be a little more prone to stalling when getting on the gas but less stalling when getting on the brakes. If stalling is an issue, try raising the idle up in small increments till it goes away. For a softer off-road setting, the lighter springs and lighter wedges will smoothly engage the clutch and let it slip longer in time as the RPMs increase. Spring rates from Soft to Hard: Steel (dull), Silver, Red, Blue, Gold.

Absolutely make sure you have some free play gain at all times. It is easy to check and you should do it before every ride and for sure any time the clutch has been abused. When you get the right feel from the clutch, then small tuning of the free play gain can slightly alter the feel, mostly the drag. This can be done in conjunction with idle RPM changes to get the perfect feel. But you must always have free play gain.

You can see here the Teflon pad on the wedge has worn so there is metal to metal contact and this causes the aluminum disc to wear down. This EXP was functioning fairly well considering this level of wear, but it and the Teflon pad on the wedge needs to be replaced. This is a very worn ramp on the EXP disc. Inspect the EXP plate for wear in the channels the wedges slide in. We have seen wear develop in 100 hours with some abusive riders (or contaminated oil) and have a few bikes with over 500 hours that show very little. We have not seen too much difference in wear based on the specific oils we have used. Yet we have always used high-quality motorcycle oil, and if not, the go-to is 15W40 diesel truck oil. Rekluse now sells its own synthetic oil and they of course recommend that. The area to look closely at for wear is where the Teflon (ball bearing rollers on very old EXP units) slides onto the ramps.

Rekluse has an excellent and in-depth manual on EXP disc assembly, inspection, and wear that you can view.