I put Sedona Ripsaws 26x9x12 on all 4 corners of my 570. I noticed a loss in power due the the extreme weight but the worst issue was when I was climbing a mountain trail at about 5000 feet elevation the belt started to burn just trying to maintain speed. I put in a Dalton kit and solved the problem. Bottom line is once these tires are worn out I will be buying stock tires or at least tires that are light like the stock ones. Also will return to stock clutch kit. My original belt last 10 thousand kms

 

So what did the clutch kit do to your rpm? Does it run at higher or lower rpm than stock? How about on take off from a stop, does it rev higher? These are the answers I'm looking for.

John

 

It puts your gearing into the correct power band for the rolling weight and radius difference from the stock setup. Reduce the weight and your motor will give quicker rpms to the clutch to help that off the line acceleration. Drawback is that you lose a bit of the tall gearing as your clutch has already shifted out to its highest speed. Basically you'll hit your rpm limiter at a lower rolling speed.
Running 1 small set screw allowed me to run desert inclines between 35-40 mph without feeling the lugging that I did on the stock clutch with the heavier than stock wheels and tires (35lbs per tire and 2 inch increased diameter). Top speed went from a stock 58 mph to 51 mph with that tire/wheel/clutch setup. I switch to a 1 inch taller than stock tire that reduced the rolling weight by 17 lbs per wheel and now run 1 long set screw with one small set screw. Off the line and midrange are fantastic and top speed is now 57 mph. This was all done using the Dalton adjustable clutch I bought from Todd @Hunterworks. That man is like the Yoda of CVT clutches and took the time to talk to me over the phone about adjustment. Honestly, he could have just told me to read the included instructions that had general recommendations for settings, because that's pretty much exactly what I did. But that's just Todd, fantastic customer service after the sale, and a true gentleman. Extremely humble for the amount of solid knowledge that he possess. He's got a ton of videos on YouTube where he breaks stuff down to where a non mechanic like me can get an idea of how the magic happens. Getting into the clutch and installing the kit also helped me understand more how the clutch works. (hint, think bicycle chain and the cog sizes aren't separate)
Anyway,i hope that helps. I tagged Todd so he could see it and maybe share some knowledge with the group.

Sent from my SM-G986U using Tapatalk

 

X2

 

Here is a good video on the basics of how a CVT clutch system works. Understanding how the system works in general might help you understand what a clutch kit is doing. Putting heavier weights on the primary is like gearing down a vehicle after putting larger tires on. If you were to put heavier weights in, it engages the primary faster and grips the belt higher in the sheave at lower speeds. Just like regearing a truck from a 3.55 rear end to a 4.10, you will lose some top speed and run higher rpms at that top speed on stock size tires but increased tire diameter will even some of that out since your larger tires are traveling farther with each rotation.

 

Outside of extremely poor tuning that loads the engine so much it doesn't have enough power to push the machine any faster (which is more possible in a 570 than other machines), the actual top speed of the vehicle is not going to be effected at all by changing the springs/weights in the clutch. They still shift out to the same final ratio regardless, all your changing is the shift curve they follow to get there. A reduction in top speed caused by clutching indicates a problem in the clutches, or a lack of power.

If you want to use the car transmission analogy... 1st gear and 5th gear are always the same, it's 2,3,&4 that you're changing.

 

the actual top speed of the vehicle is not going to be effected at all by changing the springs/weights in the clutch.

You are absolutely right. What I was so poorly trying to explain was that your rpm limiter will hit its limit because of the increased weight and diameter of your rolling stock. I only increased my top speed because I changed the rolling stock to a leaner, lighter setup. I only adjusted the weights in the clutch to better match the decreased load from reducing weight and size.
RWB713,I appreciate you taking the time to break it down to answer this question. Was very informative and I feel like I understand it a bit better than before.

 

Thanks for the help out guys. I know the principal of how the clutch works, I just wasn't sure how the kit affected the shift points and rpm. Given that I would like lower cruising rpm and keep the top end power is not going to happen I guess.

I was hoping the top ratio (5th gear) could happen sooner with a light load (cruise at 35) and drop lower (3rd 4th) when loads increased. I know larger tires aready increase the load so maybe that isnt possible. Top speed on the 570 is power limited for sure with larger tires.

What would you say is the sweet spot in the rpm range for the engine to run?

John

 

Almost all CVT clutch tuning is based on wide open throttle, this is because that is the most consistent and desirable point to measure. You make a WOT run from a slow roll to full shift out, and record that RPM, you want that RPM to be in the engines peak powerband. I'm not certain what that speed or RPM is on a 570, but any adjustable clutch kit should give you that info.

Now, if you want to talk about the shift curve...well that's how fast the engine gets to that peak RPM after you mash the throttle from that slow roll, that is effected by the location of the mass within the flyweight, the profile of the flyweight, the primary spring, secondary spring, and secondary helix ( So...everything ).... changing any one variable has an effect on the others, be it a small effect, or a large one, and that shift curve, is what will effect your RPM at X speed and X load/throttle.

Your RPM at a given speed, say 35 MPH, will ENTIRELY be determined by the throttle applied, and the load the engine is seeing, and how those variables react into said shift curve. That is why it's almost impossible to give a guide to tune for X RPM at X MPH other than WOT at full shift out speed.

If you want your cruise RPM to drop, you need the clutch to shift into a higher gear faster, but you'll want to do that without changing the shift out rpm very much so you don't lose power to the ground when you need it. Any change you make that does this, will also be a little harder on your belt, not usually a huge problem in a 570, but the principle still applies. The best adjustment you can make to do that is the secondary helix (you want to go to a steeper angle), which is also the most difficult to tune, and can become expensive if you don't get it right the first time. The next best would be a softer secondary spring. Either of those changes have only a small effect on shift out rpm, but can substantially change the shift curve.

The issue you'll run into with a 570, is there aren't a lot of options to specifically adjust for a cruise RPM, you can contact the mfg's of the kits and see if they have any good insight, and hopefully one will be able to guide you a little better with some actual 570 tuning options. Dalton would be the first company I'd try to contact for your application.

 

Thank you for that info. I made a 100 mile trip today with the wife. That was the first time we rode together for any length of time in the mountains. I can see now that a lower cruise rpm may not be a good thing when loaded with two up and hills or longer climbs. The engine needs the rpm. I'm feeling more comfortable with the rpm as it is. Just not something I was used to experiencing.
I will say the engine feels quit smooth for a 500 thumper. The rzr feels good at around 30-35 mph which feels good on most roads. I haven't done any trails yet in low range. That will come later this summer. I'm sure it will work great for that also.

John

 

If you haven't had a full auto utv or atv before the rpm can be disconcerting compared to a manual trans where you can click up a gear or 2 and run just off idle and then shift as needed. My mom drove my RZR earlier this week and we were creeping at 10mph in high and she kept saying she didn't want to go faster because it was already revving high, just based on noise. I switched to the tachometer screen and told her to just go faster. Once she saw that it would just hold that same 3 to 4000 rpm she was much more comfortable with it.

 

Ya, the fact that a new engine was running 2000rpm under the rev limit was strange to me but I guess that's just how it is. I am getting used to it. The performance is there. A friend of mine who has a 900 said to let her rip after the first 100 miles.
You are right about it being kinda a sound thing to......revs the same all the time it seems strange.

John