So for example : 190 - 320 with 16 grams = 8000 rpm

190 - 380 with 18.3 = 8000

190 - 420 with 20.5 = 8000

What is the advantage of a heaver spring with more weight?

Where do you stop?

most people will say better acceleration....but i`ve seen 2 same sleds with one having more helix and more weight....and the other having lighter weights and less helix accelerate at about the same thing....but the OEM are using more and more harder coumpoud rubber on there belts for longer life spands....wich lighter weights seem to have a harder time grabing the belt.

but thats only my theory. :)

Adding weight while keeping the start spring pressure the same (190)will tend to lower rpm at the start of the shift curve which may be undesireable if you fall below peak torgue,if the engine can pull it all will be fine and the additionall weight will provide additional belt sqeezing forces to prevent slippage and increase effeciency.Personally in my 2000 Machz I run 200/290 spring and 27.5 grams of pin weight which gives 7900-8000 intial then approx 8250-8300 at full shiftout.

Assuming the shift force is the same at 8000 the difference would be at other rpms. For example at 7500 the heavy/heavy setup would have less shift force, but at 8500 it would have more. The centrifugal force of a lighter weight increases more gradualy as rpms increase than a heavier weight.

http://www.muller.net/mullermachine/docs/clutch1.html

marsheng man that seems like alot of pin weight there telling me to run around 19.5-20.0 with a 200-320 spring and my gearing around 24-43 secondary set at 24 pounds but i do weigh around 300 pounds. Sled is bone stock what do you think about this set-up do you think it would be better to run alot of pin weight as heavy as iam sled is a 02 machz sport 1,800 miles on it. :ohmy:

I use dynamo Joes Helix and you need lots of pin with it to hold rpm,s down,but it flatout rocks!!!!!!!!!!!!!!!!!!!!!!!!!!

I'll have to break down and get a rer sec. to try dyno's set-up :(

You wont regret DJ,s clutching as it works awesome and works under all conditions especially with heavy snow conditions or towing,heavy pulling situations and you will have cool sheave temps and LONG belt life.We started riding/ testing here on Dec 16 and I was out today on Mar 16, same belt on a MachZ with lots of Mods over 1600 miles so far!!! and belt looks great,makes you wonder when some guys only get 300-400 miles on a 05 MachZ belt.

I did not know that JOE made a helix for the 05 Mach??

I don,t believe that he does ,I was just commenting that BRP seems to have difficulty making a clutch work properly!

Originally posted by hillpounder@Mar 6 2005, 02:52 PM
...http://www.muller.net/mullermachine/docs/clutch1.html
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Super good article. :)

Originally posted by marsheng@Mar 16 2005, 09:50 AM
You wont regret DJ,s clutching as it works awesome and works under all conditions especially with heavy snow conditions or towing,heavy pulling situations and you will have cool sheave temps and LONG belt life.We started riding/ testing here on Dec 16 and I was out today on Mar 16, same belt on a MachZ with lots of Mods over 1600 miles so far!!! and belt looks great,makes you wonder when some guys only get 300-400 miles on a 05 MachZ belt.
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DJ helix is awsome but I cant get anymore than 300 miles out of a belt before it is toast. I was running 27 gm. pins but with much heavier spring. The clutches are always smoki'n hot so I dropped the spring down to 160/230 for a different approach but also had to drop pin down to 14 gm.
How the hell are you running almost the same spring with 27 pins?
I must say with the lighter pins she really comes to life in low and mid but the belt is just as hot. I have run out of testing time this year but I do like the weaker springs for sure. I wouldn't know how to react getting 1600 miles out of a Skidoo belt. The last Doo I owned that got that was the old 94 FZ and I blame low power for that.

With 1600 miles my belt is about .020 thinner than when I started and looks almost like new with no glazing or rough spots.My buds 01 MachZ with S8X also looks much the same as mine and similar milage on it also.We do not have heat issues such as you are having either so I don,t know why yours is doing that.The highests temps we have recorded are about 122deg F on the sheaves and about 167degF in the compression area of the belt.wish I could be of more help!We both use the 200/290 spring,me with 27.5 grams and him with 28 grams,holding rpm to 8250 on the long and flat.Not sure why yours reacts so much differently than ours.We have identical performance and milage as well.

Curious to what both your sled's gearing is?

23/43 for me Joey.

Marsheng, is your tach calibrated? I found 8500 is the sweet spot if not calibrated. My power is down [120 psi] so maybe next year after a new top end I will have to add pin but I sure like the pull the lighter pins give me.
Doesn't make any sence that we have the same clutching but I get no miles out of a belt. You cant be using the junk Doo Belts? I have been but no longer.
What do you weigh? I'am pulling a 250# butt around and a long track so maybe this is the problem....

We run 24/43 gearing with stock pipes and I switch to 23/43 for jaws pipes.My tach is calibrated and reads with 10-15 rpm of true,my buds reads 250 rpm high so we shoot for 8500 with it.Mikadoo I do run the 066 DOO belts as does my buddy,we both weigh about 220lbs and our machines are short tracks.My belts from last year look terrible compared to this year and many people can,t believe how my 1600 mile belt still looks so good!!I put new bushings in my clutches this year and my bud left his old ones in his,but his shifts and works just as good as mine.Not sure why you have so much heat and poor belt life.

I have the answer, buy a Polaris or Yamaha they dont have belt problems.........

Originally posted by Mikadoo@Mar 22 2005, 09:59 PM
I have the answer, buy a Polaris or Yamaha they dont have belt problems.........
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01mach- i was kind of wondering the same thing,this is what i experienced from going to the stock spring which is a 160/230,18.4 gr of pin weight,clicker #2,red/white in the sec,middle hole and a 49 degree helix-bearcat sec. with a cat belt.
-in a 01 zx chassis,144x2 track,21-44 gears with a 97 670,501 rv,shorty boots head shave,.8 mm base gasket,tunnel ported,cleaned up exhaust ports and an x/ho pipe.

1)running 160/230,18.4 gr,clicker 2 sec-middle hole,red/white,49 deg.helix, pri slightly warm,sec cool

2)changed to 180/290 started with 19.4 gr,clicker-2,--pri very hot reving to about 8600,sec.hot
3)installed a total of 21.8 gr,pri still very hot,bad backshift,
4) changed sec to #2 hole,pri the same--little better backshift but pri.is still hot.
5)installed a total of 23.9 gr.the max i could install--pri is still hot,rpm is good,sec is still warmer than before.
6)crank up sec spring to #1 hole,secondary is cool,and backshifts hard,but pri is still too hot.

can't add anymore weight-damn

i noticed that the more weight i added it pulled alot harder than with the lighter spring and less weight.it was like the sled wanted to leave me behind,sitting in the snow.
with the original setup i was running around 8000 rpm which was a little low.i moved my clicker up to #3 and my rpm jumped from a straight shift to 8000 to 8500,which really surprised me.it is almost as straight a shift as it was on clicker #2.
so i added so more pin weight to get my rpm down to about 8250-assuming my tach is about 150 high.
i am now running 20.4 gr,clicker #3 with the 160/230,with the red/white spring in the middle hole with the 49 degree helix.
both my clutch's are very cool,rpm is where it needs to be and i'm still using the same belt.about 2000 km on it.
this setup pulls harder than the 18.4 gr. but not as hard as it did with the 23.9 gr.now i've got to make a decision,buy heavier pins or maybe go with oversize rollers that weigh more.


don't know where i'm going with this but this is what i expereinced.

lighter pri spring with less weight didn't seem to have the pull your arms off torque-more revvier

Swish, thanks for your reply. These are the detailed post I was looking for.