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Hahaha! Yea, long day today. :icon16:

Todd can machine out your sheave, I'm gonna see if he can add a couple different mods to his sheaves, squeeze out a little more performance. There's always more to do on the sheaves, but it gets to a point where it becomes too much work. For awhile there I had my eye on the aftermarket clutches and I still do, but the possibilities of the Oem clutch are really good.
 

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sweet mike, I like your ideas, you are making an old idea even better, that is the rhino!...lol
Thanks. I am still working on my super sheave. And I already have a new idea for the secondary that will grip the belt without spring pressure. I used those slippery washers, both on the bottom of the spring and on the top. This really reduced the spring binding on the lighter spring and allowed it to react faster. I checked the helix, full movement with no stopping on center. Engine braking worked well.
 

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Hahaha! Yea, long day today. :icon16:

Todd can machine out your sheave, I'm gonna see if he can add a couple different mods to his sheaves, squeeze out a little more performance. There's always more to do on the sheaves, but it gets to a point where it becomes too much work. For awhile there I had my eye on the aftermarket clutches and I still do, but the possibilities of the Oem clutch are really good.
Kms does your sheave for $125 they r local to me also save me some money lol

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Went out on my first trip with these clutch mods. Most of the ride was rocks and it did great lots of low end now climbs great! Well worth the money can't wait to buy the new sheave and roller weights!
 

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Hahaha! Yea, long day today. :icon16:

Todd can machine out your sheave, I'm gonna see if he can add a couple different mods to his sheaves, squeeze out a little more performance. There's always more to do on the sheaves, but it gets to a point where it becomes too much work. For awhile there I had my eye on the aftermarket clutches and I still do, but the possibilities of the Oem clutch are really good.
Kms does your sheave for $125 they r local to me also save me some money lol

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We do them for $50
 

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Hahaha! Yea, long day today. :icon16:

Todd can machine out your sheave, I'm gonna see if he can add a couple different mods to his sheaves, squeeze out a little more performance. There's always more to do on the sheaves, but it gets to a point where it becomes too much work. For awhile there I had my eye on the aftermarket clutches and I still do, but the possibilities of the Oem clutch are really good.
Kms does your sheave for $125 they r local to me also save me some money lol

Sent from my SM-G900V using Tapatalk
We do them for $50
Yea after talking to Michael im getting your guys set up

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Thought you might enjoy this Mike. :hihi:


Pretty massive low end. See if I can push it more.. lol
Gonna have to add the belt guards from keep it from coming off lol

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Haha. It's a pretty weird feeling driving because it feels like it's in extra low range, but will accelerate to 56mph. I'm pretty sure I can get another 2.5mm, maybe 3.
 

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Put together a quick comparison between clutch modifications for those trying to understand the difference. The higher the belt comes up out of the secondary clutch, the lower the take off gear ratio. This yields greater starting torque transfer, something that generally wanted by everyone. This has nothing to do with your top speed, however your speed may be influenced depending on the modification used to get the belt to the height achieved. Stiffer secondary springs help you stay in this low ratio longer, but do not actually change your ratio. Therefore ratio must be changed through modification of the cvt system.

The first two images show belt exposure with the cvt cover in place. As you can see the Hunterworks runs at the absolute maximum belt height, just slightly below the cover (He actually uses feeler gauges to determine belt height). The more you machine the sheave, the more low end you can achieve. The bottom line; you cannot achieve lower gearing without damaging either your belt or your cvt cover. Anyone can grind metal out, proper tuning of the cvt system is key here.

Lastly is my sheave which is a highly modified version of the Hunterworks sheave, fixed sheave and secondary. Many of dunes/rock crawler drivers do not use their cvt covers in order to keep their cvt belt temperatures low and to maximize their sheave modifications well beyond the norm.

My current clutch setup lowers the cvt gear ratio 48% lower than stock. For some reference, the Hunterworks clutch is 24% lower for the rhinos and 16% lower on the Wolverines, mainly due to the cvt cover limitations. At a reduction of 48%, I have the ability to use 31" tires and still have the gear reduction of 24% over stock. I think 27's will suffice for now and I can climb up anything in high gear while still maxing out at 56mph.

For my rock crawling, the slower the better. Horsepower sells cars, but it's torque that wins races. :hihi:

Here's some interesting reading about clutch mods pre- 2010 and who originally created them.
Nyroc's ATV info website

Link for purchasing shims: Rhino Shim Mod on Ebay






The Tinken/Camshaw X-Clutch, an experimental leap into the future of high performance clutches. The combination of next level sheave machining combined yields 12mm of belt exposure out of the secondary clutch makes for some massive low end power. It's these advances in research and development which further the performance of available aftermarket clutch systems.

 

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Very nice ! Which spring u thing will be best for duner set up

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Thanks Mike, that is a really difficult question to answer correctly!

Your cvt system should be tuned based upon your ideal engine torque curve. While spring pressure will directly affect your shift point, choosing a spring based upon your ideal shift point is poor choice. Spring size should be chosen based upon your engine's torque output, not where the shift point should be. Stock engines would use lower pressures, while modified engines will use stronger springs. Unless you are slipping your belt, less is more in this situation. Putting a really heavy spring in will only lower your efficiency causing poor torque transfer and burnt belts. Exactly the opposite you were trying to achieve in the first place.

Now, which spring? Color means absolutely nothing when it comes to springs. I have taken springs from several vendors, measured spring pressure and to no surprise, they were all different.

Here are two orange springs both from different vendors. Both supposedly from EPI.



Blue spring below is from EPI, I can confirm as I ordered it directly. The spring on the right is the oem 660 spring. Interestingly, compare the blue spring with one of my tested orange springs...



An obvious exception to the rule is being able to source weight sets low enough to match spring pressures. You might be without the luxury of having a completely optimal cvt tune. The other side to that coin is that it may be advantageous to set your shift for mid torque curve rather than at the top. While this will yield a little less acceleration, it may provide a little more on top.

My suggestion is to try to run as light as a spring as possible. Then choose weight size to determine your shift point. Experimenting might prove better than tossing in a generic orange spring.
 

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Damn that's crazy they do that. they just paint them without testing them prolly lol on our last dune trip I tried a purple spring I didn't like it u could tell it was too stiff . I may try putting stock one back on and see how it feels

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I should also prolly add a tachometer to see my rpm's

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Unfortunately EPI no longer sells lighter than a blue spring, no more red springs. Red springs have the exact same shift point as a blue spring, but they are lighter pressure 1.75" so you get a speed boost with the light rollers. I will try to source one for you to try, it's what I use.
 

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Sounds good thanks

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