2013 sleds

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techsledder

Member
raceinsnow said:
... but if there is a problem with the belt or if it falls off I would like to have the break assembly on the drive shaft so I could stop.
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Yeah I was wondering the same thing. How do you stop if that belt breaks. Hopefull you'll just roll to a stop or you'l be in the spot to roller' on it's side and come to a stop the 'ol Rasmussen way. There must be a space limitation that they ran into on either side of the drive shaft that made them move it to the jackshaft? I'm guessing the weighed their odds of it actually breaking vs. the cost of shoe-horning that brake system into a spot on the drive shaft.

CMX's system has the brake integrated behind the trackshaft's gear. Nice tight package. http://www.crazymtn.com/sifiso/pages/cmxds.html
 
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7

7707

New member
raceinsnow said:
I like the idea of having a belt instead of a chain but if there is a problem with the belt or if it falls off I would like to have the break assembly on the drive shaft so I could stop.
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Yah like that time you spit the track out the back,, I think you slid about a half of a mile or more before you stopped.
 
indy_500

indy_500

Well-known member
Water pump belts on the big blocks DO break. And if it does break, like mentioned, no brakes. Not sure the weight savings of 5 lbs is that big of a deal, you can just lose 5 lbs from your body instead if it's that big of a deal...
 
indy_500

indy_500

Well-known member
techsledder said:
Indy, I'm not looking to start an internet fight with you. Really I'm just asking you to do some simple research and fact checking prior to making baseless "gut feel" claims on good technology that has been used in heavy machinery and production systems for many years with success. If you need more education on the synchronous belt drives out there a good place to start is at Gates.com & <cite>cptbelts.com</cite>. There are multiple use cases and white papers there that'll share factual engineering data and they'll show you the advantages of synchronous belts over the chain drive.
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I already know about them, I've changed water pump belts on big blocks with gates belts. THose belts do break. Don't like the idea of the belt in there at all. Recoil breaks, takes out the belt....



Really, WHAT is wrong with a chaincase? Still haven't figured out that one yet...
 
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rodehard

New member
This is really going off on a tangent but I have experience with top fuel, blown alcohol and prostock racing. The blown motors use blower drive belts and some prostocks use a timing cam drive belt (jessel). These belts can stretch and break but they take tremendous abuse.

The belts work as designed and work well for that purpose. You cannot and should not make generalizations like "Looks like a disaster waiting to happen".
 
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nitroman

New member
There is nothing "wrong" with the chaincase. The belt drive is simply more efficient at transfering power to the ground and it's maintenance free. Lower inertia equals less resistance to external force which equals more HP to the ground

Sprockets outlast roller chain sprockets
Maintenance free system
No lubrication
No retensioning
Quiet operation
Smooth running
Accurate and precise operation
 
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alwaysright

New member
On the braking thing, most sled (well, mine anyway) has the brakes up top, if my chain broke, I'd, kill the motor and us the compression to slow me down, just my thought, now if the track breaks then you're screwed, but I always carry a spare one in my backpack, along with a chain and extra gears, just incase.
 
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G

Guest
Chains and gears take more more energy to turn than a belt system. I have not seen the pics of the system but in order to maintain the proper tension on the belt there is going to have to be a pretty rigid mounting bracket. I would assume this mounting bracket would also house the lower bearing on the driveshaft and the upper bearing on the jackshaft. Everything will be fine. The bearings will be live. The bearing fails on the speedo side of the driveshaft because it flexes more than the chaincase side. Not because oil seeps into the chaincase bearing. On most sleds this is a sealed bearing anyway. Kudos to Pol for being the first to put this idea into mass production.(if its true) They were caught with their pants down for awhile but it looks like they are coming back with a vengeance. This is good for the entire industry. And us.
 
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switch07

Member
allen,

Now thats what I am talking about. It is apparent that you have the same experience as I do working with this type of technology. In my opinion it has taken too long for the oem's to jump on this type of belt drive system. As far as the brakes go, I would not lose any sleep over where Poo has placed the disc. I don't think of it now with the chain, and surely won't think of it with the belt. I hope it does not take too long for Poo to bring this drive system to the Rush Switchback platform as I will need a really good exuse to tell the wife why I need to upgrade again, lol.


allen_shores said:
We also use these belts(Gates Polychain) in the paper converting industry. They are almost indestructible. We had a 3" wide belt that a 1/2 x 2.5" bolt was dropped in between the belt and pulley. It popped the image of the bolt right out of the belt. As far as I know it is still running today. Were are talking like 4 or 5 years. This belt is driving a roll of paper board 70" in diameter 65" wide, accelerating, and braking with a 30 plus HP motor. There should be no problems with this belt drive system.
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olsmann

New member
I really like this idea and have no doubt that it will be lighter and stronger and im betting the belt will out last the sled. But my only concern is what about guys that like to change gearing? and how much is this gonna cost?
 
0

09m8

New member
lenny said:
hey! who's this incredible handsome guy talking about Yamaha Nytro's when you click the live upstream.
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Well, thank you Lenny! You shouldn't have! Oh, you don't look half bad yourself, even when were upside down!!
 
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tealracing16

Member
switch07 said:
allen,

Now thats what I am talking about. It is apparent that you have the same experience as I do working with this type of technology. In my opinion it has taken too long for the oem's to jump on this type of belt drive system. As far as the brakes go, I would not lose any sleep over where Poo has placed the disc. I don't think of it now with the chain, and surely won't think of it with the belt. I hope it does not take too long for Poo to bring this drive system to the Rush Switchback platform as I will need a really good exuse to tell the wife why I need to upgrade again, lol.
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Switch - you work at PCMC? I used to once upon a time. I agree with you about the belts.

Another point is that you don't have to have these style belts super tight. That's why they have the teeth on them. So no tensioner.

Indy - If you are blowing v-belt after v-belt you need to get a tension tester because your probably way too tight. When you do this it causes the sheaves not to be lined up and you get side loading on the belt, where it is weakest. Please listen to switch07 and others and do some more research outside the snowmobiling world and I think you will find that belts are used way more often than you think.
 
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alwaysright

New member
olsmann said:
I really like this idea and have no doubt that it will be lighter and stronger and im betting the belt will out last the sled. But my only concern is what about guys that like to change gearing? and how much is this gonna cost?
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Most likely you will have to buy 2 of the 3 compenents to make it work due to no tensioner. either one up tooth and one down tooth on the gears and use the same belt or one gear with different tooth and a different belt to keep it tight. One more way for poo to make some extra bucks in the parts dept. aftermarket should have them too with a better price.
 
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G

Guest
Saw the pics. Thanks. Looks like a very simple and straightforward design. Hopefully they will all have it soon. Yami won't be able to do it with their 4's but the other 3 can all do it with their reversable 2 smokes. 5 lbs here and 8 lbs there and pretty soon you have a 400 lb 800cc sled. Cool.
 
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switch07

Member
teal

Yeah, 32 years and counting at PC. I travel now servicing our equipment all over the country/world. Kind of cuts into my sledding trips, but it also pays for the toys,lol.


tealracing16 said:
Switch - you work at PCMC? I used to once upon a time. I agree with you about the belts.

Another point is that you don't have to have these style belts super tight. That's why they have the teeth on them. So no tensioner.

Indy - If you are blowing v-belt after v-belt you need to get a tension tester because your probably way too tight. When you do this it causes the sheaves not to be lined up and you get side loading on the belt, where it is weakest. Please listen to switch07 and others and do some more research outside the snowmobiling world and I think you will find that belts are used way more often than you think.
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