The 2017 YZ250F from Yamaha represents the highest level of off-the-shelf performance found in a modern machine. Priced at $7,699, this Yamaha is a closed-cours.

• 2017 Yz250f Owners Manual
• 2006 Yz250f Manual

For some, the clutch is just the thing that’s tied to the lever you pull in to stop and release to go. For those that understand its usefulness, however, it can be a distinct performance advantage. This is where Rekluse comes in. Sure, they manufacture standard replacement clutches, but they also have a full line of manual and automatic alternatives.

I personally tested out one of their original Z-Start Pro auto-clutches a few years back. The concept was intriguing, but I thought the overall feel of the clutch needed to be refined, as well as the simplicity of the system.

Fast forward a few years, and Rekluse has done exactly that, plus adding in a lineup of manual clutches to their catalog. So we decided to grab a few riders and bikes, then head out to Glen Helen on a Pro Thursday to test some of their clutches back-to-back. Our test fleet included a stock engine Kawasaki KX250F, a heavily modified KX250F, and a Suzuki RM-Z450. The goal was to ride each bike with their respective stock clutches, and then go through Rekluse’s Core EXP 3.0 Auto, Core Manual, and Core Manual with Torq Drive clutches to compare the differences in each model. Core EXP 3.0 (Auto-Clutch) $899.99: This is the latest version of Rekluse’s auto clutch, which utilizes centrifugal force to engage the clutch. There are actually two versions up for grabs. First off is the EXP 3.0, which is a kit that includes the EXP disc and clutch springs.

This nets you the auto-clutch capabilities for a lesser price of $399.99. To get the best all-around performance, we chose to spend our time with the Core EXP 3.0 kit. This comes with an inner hub, pressure plate, /steel plates kit, springs, clutch cover, and an EXP disc.

Hydraulic clutch actuated models include an adjustable slave cylinder as well. To some, the design of this clutch may resemble a stock clutch, except for the standout EXP disc. How does the EXP disc work? This disc sits on top of the clutch pack and below the pressure plate. Unlike a normal clutch, it doesn't haveconstant pressure. The pressure plate is adjusted to leave a gap of.035'.

This allows the wedges in the disc to expand as the RPMs rise and engage the clutch. As it expands and engages, it creates forward drive, This mimics a rider sliding the clutch lever out. Because this is mechanical and RPM sensitive, it's consistent and eliminates the human judgement. However, you can still manually over-ride the clutch. When the lever is pulled in, it still lifts enough pressure off the disc and clutch pack to act as a manual clutch.

This clutch can be adjusted in a few different ways to change engagement and performance. EXP Springs – Tunes engagement & disengagement RPM fto suit your riding style and preferred engine braking. Wedge Mass – Tunes the aggressiveness or “hit” of the clutch engagement.

Idle Speed – Can be adjusted in conjunction with EXP spring tuning, this can create a different balance of engagement and disengagement RPM. Pressure Plate Springs – For built high-horsepower engines, several spring options are available to provide more clutch clamping force, increasing the torque capacity and performance of the clutch. Andre Barbosa (Stock 250F): I immediately noticed that the Core EXP auto-clutch made the challenging conditions less stressful to deal with.

Instead of worrying about stalling in ruts and being perfect with the clutch lever, I could let the Core EXP do its magic. This allowed me to concentrate on hitting my lines and looking ahead. I never came close to stalling, despite ignoring the clutch lever the whole time, except for upshifts. One unexpected result was the feeling that the bike had a slightly heavier flywheel, and builds RPMs a bit slower. I guess this is a consequence of the clutch being slightly heavier than the standard manual, causing it to generate a little more inertia.

Michael Lindsay (Mod 250F): I personally wanted to find out how the Core EXP would hold up in a full race engine. Specifically, how it would react to the increased power.

Although this clutch makes the bike rev a bit slower, the lightened crank in this engine negated the affect, and left me somewhere in the middle in terms of how quickly it built RPMs. This did help in flat, hard-packed corners, where the stock set up would react too quickly and spin the tire. But it didn’t seem to affect the bike’s power up top and left it revving freely after it entered the mid-range. The actual lever feel was the most impressive part. The early Rekluse auto-clutches I’ve tried had a heavy and inconsistent lever pull. This setup however felt very similar to the stock clutch.

The lever pull was manageable and had a progressive feel to it. I even went over and practiced a few starts into Glen Helen’s Talladega first turn. I tried a few starts in the dirt, where I treated the clutch as a manual. I loaded the engine and slid the clutch out until the bike was itching to move, then dropped it.

The extra inertia allowed to me be a little shorter with my clutch action out of the gate, and just get straight into focusing on my shifts. In loamy dirt, I had to raise the RPMs a bit when launching to keep it from taking too long to rev-out before my shift to third. On concrete starts, the extra inertia of the clutch helps with traction and the overall launch of the bike.

Personally, I did find two minuses in this clutch. One was that the lever had to be set up with almost no free-play in it, which took some getting used to. The other involves large downhills. You have to be careful to keep the RPMs up, if they drop too low (to around idle speed), the auto-clutch kicks in and allows the bike to freewheel. This in itself isn’t too bad, but when you downshift the engine braking kicks back in so quickly it can throw you heavily off balance. It’s more or less something that caught me off guard the first time, but was able to eliminate from happening again. Overall this clutch has quite a few things going for it.

Plus, you almost forget you’re using an auto-clutch because it works so seamlessly. Riel Lafave (450): The auto-clutch is pretty interesting on a 450. Its presence is most noticeable at low speeds, as if you were lugging the bike through a rut in high gear. Thanks to the combination of the 450’s massive power and the auto-clutch’s features, it eliminates the real need to use the clutch during a moto.

Instead, you can just focus on shifting and hitting your braking points. The only time the clutch is really necessary, is when you lug the bike through a corner and need the RPMs to bounce back up for an obstacle. At which point, I’d just give the clutch a little flick and I was off. Because of the lack of use, there was also no fear of burning up the clutch and wearing it out during a long, aggressive moto.

2017 Yz250f Owners Manual

Core Manual (Manual Clutch) $519.99: The Core Manual is as it sounds, the essentials of a quality manual clutch. This kit comes with an inner hub, steel plate kit, pressure plate, and springs.

The clutch cover is optional, as it’s not needed to clear the clutch. This clutch is built to be lighter, flow more oil, and be more reliable than the stock clutch. Andre Barbosa (Stock 250F): With this setup, the bike revved quicker than with the EXP, but managing traction on the hardpack areas of the track was more difficult. Once I went back to a manual clutch, I quickly realized how the EXP Auto made my life easier in the difficult conditions.

Now I had to be much more attentive when entering the ruts, which at this point of the day were already treacherous. All-in-all, this was an improvement over the stock clutch in terms of modulation, while retaining a similar feel. Michael Lindsay (Mod 250F): This clutch felt like most aftermarket clutches I’ve tested. The action and consistency is improved from the stocker, especially during longer motos. Personally, I’ve struggled with most aftermarket clutches because of the spring stiffness. I’m not gifted with the longest of fingers (size small glove), and I struggle with having enough finger strength to pull in the lever. This is especially true when running stiffer springs that are required to manage the increased power of a modified engine.

My fingers tend to cramp, so it’s almost a decision of whether to use the clutch or not during a moto. The Core Manual is definitely an all-around improvement in performance over the stocker, but the springs were still too stiff me to be comfortable using the clutch actively. Riel Lafave (450): Sadly, Riel wasn’t able to make it to the standard manual clutch, as one of his trips down Mount Saint Helen ended with him on the deck.

The trooper let us finish our testing even though he broke his foot in the process! (We all went in different orders on which clutches we tested, and kept quiet so we wouldn’t ruin each other’s opinion) As you can see by our opinions above, the Core Manual clutch improves upon the stock clutch’s characteristics. Core Manual with Torq Drive (Manual Clutch): $899.99 This manual clutch features Rekluse’s Torq Drive technology. This setup uses 12 fibers and 12 steel discs instead or the usual seven or eight.

These discs are ultra-thin, so they don’t expand the overall width of the clutch, keeping it close to the standard size. Because of the increased control and wear resistance these plates have, Rekluse is able to use a softer springs in this clutch. Also because of the thin nature of the plates, the kit comes with these “basket sleeves” that slide into the plate grooves of your stock basket.

If your basket is worn and has notches from the plates wearing against it, this is great as they cover them. This means you won’t have to by a replacement basket, this also keeps the plate from causing any more wear on it.

This kit comes with a pressure plate, inner hub, fibers/steel plate kit, 2 sets of springs varying in stiffness, basket sleeves, and clutch cover. Andre Barbosa (Stock 250F): On acceleration this setup felt similar to the Core Manual, but with a lighter pull at the lever and a slight advantage in modulation.

Of all the options tested, this one offered the most precise engagement, with the rear wheel feeling very connected to the ground. More advanced riders that frequently use the clutch to fine-tune the power delivery would probably benefit the most from this setup. However, for a rider of my ability level I would say the most noticeable improvement is the lighter clutch pull, which translated into less fatigue over long motos. An interesting side effect of the lighter clutch pull was that it motivated me to be more proactive with the clutch, resulting in a more aggressive than usual approach to some sections of the track.

Michael Lindsay (Mod 250F): Overall, this was definitely my favorite clutch that we tested. This setup promotes constant use if you know how to use it. Sears service repair.

This is thanks to its great progressive nature, its ease of use, and consistency. Each pull is rewarding as you can feel the difference in the action throughout the stroke of the lever. The biggest positive of all was the actual stiffness of the pull itself, or lack thereof. As I stated above, this is my main problem with aftermarket clutches, especially on a heavily modified engine that requires stiff springs. Even with a stiffer set in this clutch, the pull was on par with the stocker. That makes it completely manageable for me, even over a long moto.

I’ve also been spending quite a bit of time after this test with this clutch, and so far it’s as consistent as the day we put it in. Riel Lafave (450): On the 450, the Torq Drive leaves you in a much different position that the Core EXP does.

Instead of just using the throttle, shifter, and brakes, you’re thrust into using the clutch to manage the power again. The increased control this clutch offers really improves the usage. Typically, stock clutches in 450s really suffer under constant use. They heat up quickly, and tend to slip under the strain of the torque the engine produces. Although the clutch did need some adjustments on the quick dial during a long moto, it was just to adjust the pull length.

The actual action held up great under the abuse, and the clutch didn’t show any signs of slipping. Even better yet was the light pull it offered, considering a 450 already gives you enough reasons to have arm pump. This was a big plus.

Wrap-Up So what did we learn? Rekluse has developed an auto-clutch that ‘s very similar in action to a manual.

2006 Yz250f Manual

This, plus its ability to make the bike easier to ride in rougher conditions, and its anti-stall capabilities make it a serious consideration. If it still doesn’t spark your interest, their manual clutches are a solid upgrade. Especially if you use the extra cash to get the Torq Drive system. If you want more info on Rekluse's range of clutches, check out. About the Test Riders: Michael Lindsay - is a born-and-raised moto freak and gearhead from the heart of motocross in Southern California. First swinging a leg over a bike at the age of five, he immediately caught the racing bug, spending nearly every weekend behind a gateand a lot of time on the couch while injured. While swinging back and forth between moto and the off-road scene, giving him a wide range of experience on the bike.

Of course, all of this led to one thing: Lindsay loves working on his bikes almost as much as he loves talking about them. When he’s not in the Vital MX forum or writing his latest product review, you can find him out at the track taking dirt naps, snapping some pictures, or drooling over the latest parts for his bike.

With an outspoken personality, gearhead background, and as Vital MX’s guru for product, Michael is here to share his unbiased opinion. Andre Barbosa - is a part-time photographer / videographer, part-time film student, and full-time motocross enthusiast. He started as a mechanical engineer, because of his love for all things motorcycle related, but switched to the banking industry after getting his MBA. He currently lives in Irvine, and can be found riding the local SoCal tracks a couple of times a week. Although he regularly raced Districts 6 and 34 when he lived in NYC, currently his friends call him a professional practice rider.