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The Perfect Set up for you...CLUTCHING...

Wheel House Motorsports

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either im backwards or you guys are.. lol or were all a little right, this is how i see it.

to shift out the rollers(and attached sheave) must push apart overcoming the spring. obviously this transition is not solely done by overcoming the spring, the rollers ride up a ramp to get there, so the way i view it is like this the roller is fighting the spring going up the helix with x amount of force, SO, a steeper helix is going to be fighting more directly against the spring where the shallower angle is giving the force more advantage over the spring.

From this i see the shallower angle putting more load on the motor quicker and the higher angle helix requiring more effort to overcome and open the sheaves and allowing the motor to spin with less load on it as if launching in a lower gear.
 

Betterview

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either im backwards or you guys are.. lol or were all a little right, this is how i see it.

to shift out the rollers(and attached sheave) must push apart overcoming the spring. obviously this transition is not solely done by overcoming the spring, the rollers ride up a ramp to get there, so the way i view it is like this the roller is fighting the spring going up the helix with x amount of force, SO, a steeper helix is going to be fighting more directly against the spring where the shallower angle is giving the force more advantage over the spring.

From this i see the shallower angle putting more load on the motor quicker and the higher angle helix requiring more effort to overcome and open the sheaves and allowing the motor to spin with less load on it as if launching in a lower gear.

You need to look at the roller where it contacts the helix. That is the point where engagement happens and the roller begins to travel down the angle. If the angle is 36 that is a rather shallow angle. When that angle increases to 46 that is steeper and the roller can travel down it easier. I know it can be confusing unless you realize the roller starts on the helix and travels down the slope, not up the slope. As further proof the newest version (2012, 2013) of the Arctic driven can not use the popular 36 helix because the shallow angle gives such a long slope it does not fit.
 

Whimp

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Dooin it... I can see what you are saying with load on the motor etc but my main concern is the rate at which the helix is shifting.... With the CVT you are constantly changing your gear ratio which results in the things you mentioned above... Everyone has there own take on it but the reason I like the lessor angle helix to start off with is the delay it creates on the shift....The lower the angle the slower the shift... The higher the angle the quicker the shift... With my turbo set up I want it to "hang" in the lower gear as I am playing in the trees etc and then shift out and gear out on the top end quickly... Back 4 or 5 years ago guys were achieving this by grinding a flatspot on their primary weights which would cause you to hang on the weight and stay in a lower gear.... so to say... Then we all went to the progressive style helix set up because of the smoother transition/shift while still still having the bottom end.... I also tend to run a higher rate starting spring in my secondary to help delay this shift even more....

When we start talking about the amount of "load" you are putting on the motor we should always remember where we are in our gear ratio.... The 36 degree with a stiffer spring will put more load on the sled but we are also at a very low point of our gearing ratio which makes it easier on the sled..........

Running a steeper initial angle will create a rapid upshift which may be less stress for the clutch to shift so to say but it is causing you to change through your gearing ratio much quicker which changes into more load on the motor sooner. liking running around in a higher gear on the bottom... Although this may be a very good set up for climbing and drag racing it does not promote the "low gear" I like to create for playing in the trees etc....

thats my take on it....
 

Whimp

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now lets start talking primary set up/ weights/ spring rates/ weight profile/ positioning of weight throughout the profile and then discuss the correlation of how this all effects the secondary set up.... oh ya
 

WyoBoy1000

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I never got light tips to lock down and make the secondary work, to erratic on the M, they seem to work better on the PC but still not as good at the MDS.

It think if you got a sec spring with a harder start rate and same finish with your helix it would increase bottom end snap with heavy tips and way more pull on top. That way the heavy shift has a stall off bottom.
 
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Crusty82

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Jan 27, 2010
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I am running a shockwave on my 2013 800 cutler turbo. I have two sets of ramps. The one set of ramps are straight and the other set is a 5 degree step ramp meaning 44 for the first bit of the ramp then dropping to 40 the rest of the ramp. Trying to get them to cut me a reverse set of ramps in the 5 degree though. The step ramp wont work very good I dont think, but I did run it a little with the stock blue secondary spring. Was not to bad just not the pull on the bottom like I like. Next ride out will be the straight ramps and a orange cat secondary spring. Hopefully this will get the bottom end up and going. The reason I want to try the shockwave is I run trails in a few places I ride to get to the good stuff. I can adjust the helix and run a lot lower rpm going down the trail to conserve fuel and then dial it down to play.

Have you been doing any more testing on the shockwave helix?
 

w2bridin

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I am still searching for a good setup. I started with 80 gram cat weights and 36-46 ran good but thought i maybe was missing something went with mds setup running 36* and the primary spring from mds (a black and a gold i tried) it had good track speed but seemed to be lazy. I then switched out the 36* for a 36-42 and seemed better. It seems like with the 36* in i need so much bolts added to weight to keep rpm down it gets real lazy.
I see a few are using the mds on m8t wondering if anyone has a new hot mds setup? I am running 10-12 psi at 8000+ ft
 
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INDEEP

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Nov 26, 2007
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Post Falls, ID
2010 Twisted M8
7-9 lbs
3-7000ft.


Mds loaded in tip 80g
100/330

34/42 helix
Orange Spring

Stock gears

Not much time on this setup but I immediately ordered a 120/330 and a 140/330 spring. 100 was too soft for my liking.
 
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Speeedracer

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Great comments, i just wish there was more definited product results available for riders who want what you started out in this post, run moderate boost...8psi....and want to boondock but still have the mid and high rpm power....all the results are so abstract, if this, then that.....etc

given that desire of an outcome, is it that difficult to sell a working package that includes prim/sec springs, weights, and a helix

...running a 2012 pc w BD, 110 fuel....
 

Hardass

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I would think you could put together a package based on 8 pounds that work well kind of all around as it seems thats what you want there are a ton of people running pump gas as its called set ups that should be about what your after Start a thread asking just that i mean just what your looking for ask others to stay out.
 
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Kyle91rs

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Jan 23, 2011
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Well that was pretty good reading ... Then it just died... Wth?

Any word on how the shockwave helix held up?

I'm running 2012 proclimb 800
10-12psi
Boondocker green spring.. (Unsure of start/finish rates at this time)
Cat 80g's

Stock secondary for right now.

Gonna be switching to a set of adjustable heavy hitters. Base weight of 68g with a pile of adjustability.

Gonna start off with 75g in the tip, and gradually disperse more weight throughout the arm as needed. See how that works. It'll be tip heavy but not all the weight in one location

Anyone have any suggestions with my secondary? I'm thinking about a 40/44 or 38/44 or something along those lines. I'm no clutching expert but from what I've read here, that sounds like I'd be on a good starting point.

My style of riding is all over the map. I like climbing, boondocking, tree riding. Pretty much everything depending on conditions. So for me to clutch for one specific riding style, wouldn't be any good.

So what I've tried piecing together so far, is that a secondary spring controls engagement, for dual angle helix's, say 40/44, 40 angle is your initial engagement angle, with less of an angle puts less load on your primary, when the rollers get to the 44 angle, that's about when up shifting occurs, higher the angle, the harder the up shift? So ideally, something like a 38/44 helix would be better? With a lower initial angle it shouldn't engage as hard, making on and off throttle chops a lot better, for tree riding say, but for the 44 angle it makes up shifting harder so you still have that rip your arms off feeling? That sound about right to you guys?

And if I ran a straight cut helix like a 44 or 46, then ideally that would put more strain on my primary, causing belt temps to rise, and we all know what happens then....
 
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Paul Tupper

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Mar 19, 2008
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I'm in same seat. With the 2014, changed the top gear to 20 though. Still confused on where the angle is measured from in previous posts. But thinking the same. The stock 36 not loading the turbo. Also mostly tree riding with a few climbs. BD kit. Lower boost.
 
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samsquatch47

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Dec 2, 2007
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St. Paul, AB
On My 12 M8 I'm running the TAPP primary with the Team Tied secondary, TSS turbo (GTX 2863) at 10psi straight 100LL fuel and Bikeman head with high comp domes. I know I know why don't I have the turbo domes?... Cause I tried them and it made bottom end suck! Response is now sick and pulls harder at 10 now then it did at 12-13 with the turbo domes. Love the TAPP primary, has quick clickers like a DOO TRA and Team seems to back shift nicely. Rpms are now very consistent. Have to see what I'm running for springs, but it was just what TSS runs in there own sled.
I mostly ride at about 6000 elevation in Valemount and McBride BC in all types of terrain. Combo seems to work great!
 

big-zig

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Clutching Theory

Ever wonder why there are so many companies and theories on clutching...

The basics of CVT... Front clutch = RPM sensing. Secondary = Torque sensing.

Basically, in the secondary the flatter (lower angle) the cut the slower it will shift out (all things equal). The result being the secondary needing more force (from engine)to shift out rapidly. In most engines "more force = more hp" and most gas engines make more hp higher in rpm band. This is one reason lower hp machines generally have flatter (lower angle) helixes. It's to get the engine into it's optimum powerband quickly.

Conversely, steeper angle helixes will shift more quickly (all other things equal) and are generally suited to higher hp engines or engines that produce high TORQUE early in there rpm range. The drawback to steep angle helixes is the backshift, it is more difficult for the spring to "push" the rollers back up the ramp. Backshift is crucial to quick throttle response and "snappy" feel.

Generally, straight line drag racers prefer steep straight cuts because they don't care about backshift. Bump racers and hillclimbers generally prefer flatter angles because they are off and on throttle constantly and rarely get over 100mph.

The primary clutch is rpm sensing ONLY. Ideal weights and spring in primary control rpm. The variable is belt squeeze because slippage = heat. Slippage can also be caused by belt durometer (hardness) and tacky-ness of belt.

In turbocharging, the hp curve increases exponentially once boost is being produced. It is difficult for the secondary to react quickly enough with a straight angle helix. It can only be good for one side of the shift, beginning or end. The compound or multiangle helix isn't perfect either though because of the increased difficulty in backshifting and causing engine to fall off it's power curve. Balancing upshift/backshift with engine limits is what makes clutching such a difficult process and explains why there is not one setup that works for everybody with a given setup.

In a perfect world your machine would be geared for your realistic max speed, upshift/backshift would match riding style and belt life would be long.
Gearing to tall (speed you will never see) only results in short belt life and lots of heat (slippage) because primary clutch will spin at intended rpm but secondary doesn't sense enough torque (pull on belt from primary) to shift completely because of resistance in gearing, track, and suspension variables.

Most clutching setups try to hit these goals but few actually do. The main reason(s) they fail is most try to work within confines of compromise due to increased expense for buyer like cutting helixes and gearing changes.

The point of this long winded post is to give s glimpse into the complexity of clutching and a salute to the companies that "get it right" through knowledge and testing.
 

Catman 42

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Nov 27, 2007
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Yakima, WA
06 M7 BB 162

Drive: Spring SLP GRN/PNK D&D Magna Force 1223 from the heel
Driven: STRT 44 Team BLK/YLW spring
Diamond Drive: 57/63 gears
12-15 psi on 100LL
6-7000'
Eastern Wa.
Elko NV.
Island Park
 

av8er

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09 Twisted M8-174x2.5CE

Climbing, boondocking.

Twisted extreme , garrett 2871, running 10 psi on 100LL
79G heavy Tipped big dog weights
black spring in Primary, guessing it's stock
Twisted BDX- SS -helix- 36/48 progressive
with a Orange cat Spring

4-8000 feet
this setup is a little weak on the bottom as most m8's, but hits hard in the middle and top end. with Stock gearing.
 
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INDEEP

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Nov 26, 2007
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What's the rate of the Twisted primary spring? I'm currently running the BDX 170/330. I don't have anyway of measuring it but the Twisted springs free length is almost a inch taller and feels even heavier than the 170/330.
 

Whimp

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Laurel Montana
springs

Hows your engagement with a 170# spring? A little jumpy? I try to stay between 120-140 for engagement.... Of course weights play a part in this too..... Shain has run a few different primary springs... What color is the one you are referring to? I really like the SLP springs... Their Blue/Pink is an awesome spring for the M8... It is a 120-320... Very nice smooth engagement and still plenty stiff on the top.....

I run the slp green/pink in my 1200T...
 
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