z-Start auto clutch - AWESOME!

I finally got the z-Start auto clutch from Rekluse http://www.rekluse.com/ for my XR650R and had a chance to test it out the other day. The z-Start auto clutch enhanced my riding experience and is a product I won’t be without again. Installation was pretty simple and probably took me about two hours, but I was taking my time. Now that I’ve installed one, I could probably do the whole install in less than 40 minutes without much trouble. You do have to be very careful to not to drop any small parts inside your engine and you should be a bit mechanically inclined, but the average do-it-yourself type person who has good common sense and good tools can install and configure this product by themselves.

The idea of an auto clutch for my XR650R didn’t sound all that appealing more than year ago, but then the idea started to grow on me after giving it more thought and reading the comments from other auto clutch users with CRF450’s, YZF’s & KTM’s just further enticed me. Now that I’ve ridden with one, I won’t be without it on any bike I own from now on. I like my big CT70 (hehe!), but there’s much more to the auto clutch than simply being able to idle in gear. Once you spend some time riding a z-Start’d bike, you may be hooked.

I thought it would take a long time for me to break my 30+ year habit with using the clutch, but riding with the z-Start felt more natural to me than riding without it after a few hours of playing around, especially on technical terrain. You can either twist the throttle slowly for a smooth gentle start or launch hard just as if you let out the clutch for that perfect race start, only the z-Start does it for you automatically. It makes riding trails that much more effortless. The z-Start makes the bike feel like it has a much wider power band, and therefore you feel like you’re in the sweet spot more often than not with less shifting and fiddling with the clutch. If you ever thought about gearing down to a lower ratio for trail use but didn’t want to give up any of the top speed from the stock gearing, then think twice about the z-Start because it makes simple work out of riding technical terrain. You don’t have to worry about stalling the bike or lugging it at too low of RPM when going slow, because the z-Start automatically clutches and declutches so elegantly that you won’t know its happening. I was more relaxed riding in technical terrain with the z-Start than I’ve ever been.

At one point while climbing a gnarly hill in 2nd gear I hit a rock near the top which pitched me a bit to the side and brought me to a halt about 12 feet from the top. Fortunately this last portion of the climb was significantly less steep, but my bike would have stalled for sure in 2nd gear had I been using the stock clutch when I hit that rock and from there things would have been very unpleasant. I pictured myself cart wheeling backwards 40+ feet down the hill as my kids watched below. If fear hadn’t taken over and I had somehow properly reacted by slipping the stock clutch setup at the right moment while trying to stay atop what felt like a bucking bronco on the side of a hill, then maybe I could have climbed out without incident, but I doubt it. I was at the point to where I was ready to let go of my bike because it should have stalled at that point. The z-Start seamlessly clutched and declutched for me to prevent my bike from stalling at that brief critical moment and I was able to twist the throttle and climb out of trouble while holding on for dear life.

I never realized how much I used the clutch or how often I shifted gears because it just happened without thinking for the most part like driving a car with a manual transmission, but now that I’m aware of this I can see it happened much more often than I ever thought. The z-Start doesn’t give your bike an automatic transmission, but you’ll probably find yourself shifting a lot less often and feel more confident in some situations as you get used to piloting what feels like an XR650R automatic when it comes to certain types of riding.

The z-Start is user configurable for different stall and engagement speeds to meet a wide variety of needs. If you buy the optional clutch perch adjuster, you still retain the use of your existing clutch and you can adjust the stall speed externally by turning a threaded adjuster that fits inline with the existing clutch adjuster on the stock perch. For my general purpose fun and trail use, I chose to set up my z-Start with low stall, quick engagement and to lock up harder more quickly, but there’s a lot of flexibility in the way you can setup your z-Start if you choose to. It’s hard to put in words just how kool this product really is, especially when I couldn’t see the point of a product like this early last year. If you ever have the chance to try out a z-Start’d bike, then take the opportunity to see what it’s like for yourself. It may be more fun that you realize!

Look for a review of the z-Start in Dirt Bike magazine (XR650R) and Motocross Action (CRF450) in the coming months.

Received my Z-Start last week. I will try to find time to install this weekend. Al called me this afternoon with lots of informative new information. Are you using the medium or heavy spring? Are you using the Steel or Carbide berrings? Did you need to use shims? Are you using the Perch adjuster? Love to hear the details of the install and adjustments? Enquiring minds need to know? :)

I have the clutch perch option and I'm using the light spring for low stall speed and slightly quicker engagement. I tried the steel balls and liked it. Then I tried 4 Ti balls and liked that too. I tried 12 Ti balls and it seemed a bit much, but I only got a few minutes on the 12 Ti ball setup before we had to leave, so I don't have a real good feel for that setup. I haven't tried any other configurations yet other than adjusting the clutch perch adjuster as I ran out of time, but I'm very impressed so far.

The install seemed straight forward to me after reading the instructions a few times. I received my kit several weeks back and things changed a bit since this time, so my drive plate is currently a different thickness than yours and my shim profile is also different, but I think I'll be getting the updated parts at some point in time :) so I'll be setup like everyone else :D

Besides the measurement discussed in the book (center ring to top of friction disk), Al had me measure the installed gap between the z-Start friction disk and the drive plate. He said the idea was to set that gap as close to 0.040 as possible using shims.

In order to properly measure the installed gap (z-start installed), I had to insert feeler gauges in one side of the clutch between the z-Start friction disk and the drive plate and install a 2nd set of feeler gauges of the same thickness on the opposite side of the clutch between the z-Start friction disk and drive plate. Another point about this measurement is to make certain that the balls are all seated on the inside (not in the outside position) so that the top plate is properly at rest. When the z-Start is brand new, some of the balls may stick in the outside groove until its broken in a bit and if you try to measure the installed gap with a few balls in the outside position when the rest are on the inside, then you'll get an innacurate measurement. Al has been super helpful, so send him an email or call him with any questions you have or I'd be glad to answer any more questions as best as I can. I'm located not too far away from you, so if you need any install help, just send me a PM.

They seem like a fantastic concept

Sounds Great...

How does this product compare to the Revloc auto clutch?



How does this product compare to the Revloc auto clutch?

I don't own a Revloc nor have I ever rode a bike with a Revloc, but I did consider a Revloc and EMF when looking at the z-Start. The z-Start from Rekluse Motorsports is the least expensive autoclutch at $399 and its got a lot going for it. The parts appear to be very high quality and everything fits like a glove. It's similar to the Revloc in that it also uses the inertia of steel balls to engage the friction disks, but the z-Start design limits the maximum clamping force to a specific level as opposed to the Revloc where the clamping force continues to increase with engine RPM. If my bike was riding through the mud and my rear tire was spinning like crazy at a higher RPM, but then all of a sudden it locked up, that energy has to go somewhere and I liked the idea of the z-Start limiting the clamping pressure as opposed to having more of that energy transmitted through the gear box. The z-Start has nearly double the clamping force of the stock clutch and I'm more than happy with that. The z-Start simply replaces the stock pressure plate and is pretty simple to install if you've got average mechanical skiils and some good tools. It took me about 2 hours to install mine, but I could now install it in under 30 minutes on another bike and its configurable for different types of riding. The z-Start by itself requires the rider to use clutchless shifting, but Rekluse also sells a clutch perch option that allows you to retain the use of your stock clutch lever and also adds easier adjustability to the z-Start with a barrel type adjuster that fits inline with the stock clutch cable at the clutch perch. It's very trick and easy to use. I really like this product and I can't wait to go riding again in a few weeks :)


Keep the info flowing. I got my name on Al's list and will finish the order when I finally get bedding down in VA. Kind of glad I waited, as products like these tend to refine themselves over time. Bet it's a godsend in the woods.

Bet it's a godsend in the woods.

Most definitely! :)

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