2013 XM 163 geared down?

maxwell

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The XM runs 19/52 ( 2.74 ) gearing? Poo runs 20/42 ( 2.1 ) maybe it's true that the Poo clutch squeezes the belt harder to be able to run way higher stock gearing.

If that were true ( which it's not ). The Polaris would have way higher track speeds. There are some things your not taking into consideration here. Drive clutch diameter, driven clutch diameter, driver diameter. This all effects gear ratios. Not to mention the skidoo spins a .25" deeper track that is 1" wider (also heavier). The skidoo can spin this track at the same speed as the pro rmk. Gear ratios are meaningless to compare unless all variables are the same. What we do know for sure is the skidoo can spin a larger heavier deeper lug track and the same speed as the Polaris. So 20/42 gearing means f all. Except the sled has piss poor bottom end in comparison


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Deano670

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Yes in order to run the 23/49 you will need to buy a 106 chain which I have in stock. Would also recommend checking the gap between the move able sheave and belt with the belt pushed tightly against the stationary before going with this gear combination.

Deano
 

trench

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If that were true ( which it's not ). The Polaris would have way higher track speeds. There are some things your not taking into consideration here. Drive clutch diameter, driven clutch diameter, driver diameter. This all effects gear ratios. Not to mention the skidoo spins a .25" deeper track that is 1" wider (also heavier). The skidoo can spin this track at the same speed as the pro rmk. Gear ratios are meaningless to compare unless all variables are the same. What we do know for sure is the skidoo can spin a larger heavier deeper lug track and the same speed as the Polaris. So 20/42 gearing means f all. Except the sled has piss poor bottom end in comparison


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You still don't get it, due to the location of where the arms pivot from causes the clutches to have the exact opposite operational efficiencies. The Doo clutch grabs way harder at low RPM that's why they are so good for drag racing, the Poo clutch has less clamping force at low RPM but more at high RPM, these are well known facts.
 

lilduke

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You still don't get it, due to the location of where the arms pivot from causes the clutches to have the exact opposite operational efficiencies. The Doo clutch grabs way harder at low RPM that's why they are so good for drag racing, the Poo clutch has less clamping force at low RPM but more at high RPM, these are well known facts.
When you;re climbing a hill or hit some deep pow your CVT is going to shift down into that skidoo superior clamping Zone any ways...lol
 
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lilduke

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What Is the "clamping force" of the stock pro primary clutch in PSI at full Shift?
 
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maxwell

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Also. More clamping force will cause the belt to go higher in the sheave = higher track speeds. But HP limits this.


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pfi572

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Doo has a over drive primary and that is why they can run higher ratio gearing. (Geared lower)
The new ones are geared a bit to low but that was to save on belt wear and heat.
It took them quite a few years but finally got it and went a bit to far. IMO
 

rylester331

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ya are you sure? the parts fiche shows 19/51. same as last season
Hey maxwell do you know anyone with a 19 and 51 for 2009 summit xp ? And another question I got the 163 by 2 1/2 non ported !! Do I need to put a 7 tooth driver in ?
Thanks
ryley
 

maxwell

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Hey maxwell do you know anyone with a 19 and 51 for 2009 summit xp ? And another question I got the 163 by 2 1/2 non ported !! Do I need to put a 7 tooth driver in ?
Thanks
ryley

Nope no need do the 7 tooth driver. Is it a 2.86 factory pitch track or 3.0 pitch aftermarket track?

And no I don't know anyone with that combo...running it in a 2011 but not a 2009. You want to run that combo? I would suggest 20/49


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Winter Brew

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Doo has a over drive primary and that is why they can run higher ratio gearing. (Geared lower)
The new ones are geared a bit to low but that was to save on belt wear and heat.
It took them quite a few years but finally got it and went a bit to far. IMO

Yep, they overshot that sweet spot for the TRA on a mountain sled. But belts will last forever with the tractor gearing.
Another reason Polaris gears a little taller is the use of the Team secondary that cannot hold onto the belt at full shift....they want to keep the belt up in the secondary to avoid ever using the bottom of the sheave and getting huge slippage...IMO
 
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