Better Understanding of Todays Track Lengths

[Sidewinder]

UGHHHHHHHHHHHHHHHHHHHHHHHHHH , Im so confused .
Jim make 100% sense with the 40% of track on the ground , I agree 100% with this .
The weight to power ratio I get , being a drag racer I know this stuff .
I understand turbos again drag racer . as well I have a chassis dyno so I understand power ad how to make it .
I just dont understand how guy claim that a 137" track can out MPH a 129 with the same HP and gearing .
Dont give me the 2 lugs more stuff , I dont see it making all that much of the difference , Ill be studding my sled either the 129 or 137"

As a ONLY trail rider and tight corners here in this area and some lakes when we go north the choice is hard .
I Dont go off trail , the only time last winter I went off trail with my Apex was to take a leak , when going back to the trail I followed another set of tracks , BAD IDEA , I hit a white trailer buried in the snow , cost me 1000. to fix the sled to go back out riding 1 more time , thats one expensive piss .
A arms , Carbide , bulkhead repair kit from Barn Of Parts and bolts .
I like to ride fast , when on the lakes we kill it , we have both ran in radar runs her 03 rev 113.7 in 2000 ft , my Apex 118.3 in 2000 ft with my fat butt on it .

I had the 14 Viper I bought in January 137" track , not fast enough , 85mph stock , 90+ with the 8DN belt only on it , TERD.
It didnt corner bad I guess , it turned better than my 121 Apex , but that was really nose heavy , 2006 RTX , fast but it would give you a good workout in the twisties .

I have a few more days to figure it out , or Ill just call the dealer and say " surprise me "

 

[Pstn head]

UGHHHHHHHHHHHHHHHHHHHHHHHHHH , Im so confused .
Jim make 100% sense with the 40% of track on the ground , I agree 100% with this .
The weight to power ratio I get , being a drag racer I know this stuff .
I understand turbos again drag racer . as well I have a chassis dyno so I understand power ad how to make it .
I just dont understand how guy claim that a 137" track can out MPH a 129 with the same HP and gearing .
Dont give me the 2 lugs more stuff , I dont see it making all that much of the difference , Ill be studding my sled either the 129 or 137"

As a ONLY trail rider and tight corners here in this area and some lakes when we go north the choice is hard .
I Dont go off trail , the only time last winter I went off trail with my Apex was to take a leak , when going back to the trail I followed another set of tracks , BAD IDEA , I hit a white trailer buried in the snow , cost me 1000. to fix the sled to go back out riding 1 more time , thats one expensive piss .
A arms , Carbide , bulkhead repair kit from Barn Of Parts and bolts .
I like to ride fast , when on the lakes we kill it , we have both ran in radar runs her 03 rev 113.7 in 2000 ft , my Apex 118.3 in 2000 ft with my fat butt on it .

I had the 14 Viper I bought in January 137" track , not fast enough , 85mph stock , 90+ with the 8DN belt only on it , TERD.
It didnt corner bad I guess , it turned better than my 121 Apex , but that was really nose heavy , 2006 RTX , fast but it would give you a good workout in the twisties .

I have a few more days to figure it out , or Ill just call the dealer and say " surprise me "

I beilieve you'd be happier with the short track, 129" I still think the shorter the track the better for the twisty's like Muskoka, Barrie, etc. ( I assume those areas being your location Ontario) On the lakes and up North so what if it's a "few mph slower" than the 137", just think you'll get to lake before your buddies so you'll have to wait for them anyway. Lol! Just my 2cents

 

[cannondale27]

You guys are making my brain hurt....lol
One question tho
In the Viper or Cat is the 137 faster than the 129?

I have not seen the faster 137's or 141's on the Vipers at least on snow since they are snowmobiles. I tend to agree with JimD especially since I own a 129! Many have heard the tale. Last winter about 10 of us Viper owners went to Wausau. Various length sleds 129,141,137 all had various bolt on mods. ALL went 101mph or within 1 or 2 of it. Freakiest thing I have ever seen. Actually thought there was some type of speed limiter on the sleds. It was just conditions and maybe the sled itself . Conditions have more bearing on speed than almost anything. The more power you have the higher the speed conditions determine the speed but it will be the conditions outside that determine the speed eventually Everytime. Be it wind,snow,ice,grass or even gravity.

 

[uprider800]

Here is my take. If you ride big trails or are a trail cruiser get the 137. If you run tighter trails or want to ride more aggressive and enjoy the fun factor of more transfer get the 129. If I didn't ride with the guys I would stick with the 137 because the stability is awesome. Plus just cruising in tight woods isn't a problem with the 137. Maybe I'm just trying to fight off farther time and thinking I can still ride somewhat aggressive. I figure I will give the 129 a shot.

 

[SRXracer]

Just measured my 137". from the center of the front wheel on the rail to the center of the rear axle is only about 36". That is actually only about 26% of the track on the ground for the 137. But, assuming the front wheel on the rail stays in the same spot, pretty much 50% of the additional length from 128 to 137 or whatever length the track is would be added because you are basically adding the length to the two portions of the track that are parallel to the ground - i think.

Also, FWIW, one of the yamaha techs at the show said the bigger the circle of the track (length), the less resistance it has to rotating, and would be faster. Personally, in the real world, I think there are way to many variables for one thing to be the controlling factor.

 

[Mike P]

I have not seen the faster 137's or 141's on the Vipers at least on snow since they are snowmobiles. I tend to agree with JimD especially since I own a 129! Many have heard the tale. Last winter about 10 of us Viper owners went to Wausau. Various length sleds 129,141,137 all had various bolt on mods. ALL went 101mph or within 1 or 2 of it. Freakiest thing I have ever seen. Actually thought there was some type of speed limiter on the sleds. It was just conditions and maybe the sled itself . Conditions have more bearing on speed than almost anything. The more power you have the higher the speed conditions determine the speed but it will be the conditions outside that determine the speed eventually Everytime. Be it wind,snow,ice,grass or even gravity.

I find "conditions" to be the equalizer, "rider ability" to be the multiplier and "mods" to be the advantage.

 

[Sasquatch]

Curious as the tipped rail lifts the last 5 or 6 lugs off the ground so 16.62 or the same as a 121. Don't see the 146 being less then the tipped 144

 

[03viperguy]

nice valuable info right there, awesome!

 

[Blueaway]

Thanks for all the info everyone . I was a little worried about my decision on a 129.sidewinder. You made me feel way better I do most of my riding on tight twisty trails. That's why I picked a 129

 

[RJH]

UPrider..a longer front arm takes away leverage..of lifting the skis ..so...less power pushing down.at the point the where the arm is connected to the rails

So..if it was an oval sled..the front skid would suck up faster when you let off..push harder when you are on it

 

[RJH]

Jim..one of the biggest factors today ..as all tracks are turds today.... is track pitch...less turning drag..that is track turning

My old Ti coated cleated tracks weighed about 12 pounds..

I personally am a fan of the short track models. For top speed, you cannot beat the short track. Rotating mass is your enemy in terms of best top speed, and the track on a snowmobile is the worst method available for putting power to the ground for top end. It is basically a 40 lb flat tire, and the energy to rotate it is directly proportional to the square of the driver rpm. Double the driver rpm and you quadruple the energy needed to double the track rpm. (this is true for all components that rotate). Rotating components create a double-whammy, not only must the engine move them from a dead stop, but must also rotate them from the same stop. It has been estimated that a single pound of rotating mass is equivalent to 7 pounds of static mass. This is why light weight wheels, cranks, jackshafts, etc, net so much performance gain. Removing the heavy reverse gears in our chain cases would provide an increase you would feel on the trail.

So, adding 10 or 15 pounds for a 137 vs a 129 would be like adding 70 to 105 pounds of static weight.

The real advantages of the longer tracks (129 vs 121, 137 vs 129, etc) are the stability of the longer wheel base and the marketing appeal to the snowmobile buyers. The longer wheel base creates less transfer (skis down) and more high speed directional control. Manufacturers have also increased the pitches in an effort to save the expensive rods and clips (less are needed as you increase pitch) in an effort to give buyers what they want and still control cost to a certain extent. Interestingly, a longer pitch tends to create a more choppy radius as the track bends around the drivers and back wheels. At some point, too much pitch creates excessive bending forces.

I find that many people overestimate the amount of track on the ground as they contemplate the longer options. A 162 vs a 129, gives a track length increase of 33 inches, but only about 40% of the extra length is actually on the ground (40% of 33 inches = 13 inches). The rest is above the ground and over the top idlers and lost from in front of the approach angle of the rails. You can see that the difference in 129 vs 137 or even 141, is essentially immaterial. But, the added weight of these longer tracks is significant!

I think you will find that the guys and gals with the 129s are not feeling disadvantaged off trail as they follow their 137 and 141 tracked friends.

For what its worth,
Jim from Canton

 

[RJH]

Port parts..stunning wealth of information..

You see I am just happy with my 99 Phazer and my flip phone. But we moved into smartphones as the era of apps and control fascinated me..we even control our other land phones with it today.

Similarly, I am getting left behind with 4/ technology so I spent all summer nagging YMC for a sled deal..on that note we all met at Bracebridge Yamaha and we worked out a deal.

In sno-x I have pushed for long tracks so I wanted a 137..well in the end to make things work I took a 147..XTX..(with a low windshield).

Your information really helped to answer many questons..

At what angle does the 147 come off the drive compared to the 129?

 

[RJH]

Did Yamaha tighen up the clutching for the 147 or is it the same as the 129.

 

[blueironranger]

Curious as the tipped rail lifts the last 5 or 6 lugs off the ground so 16.62 or the same as a 121. Don't see the 146 being less then the tipped 144

I like the tipped rails on my 144" Phazer, seems to corner just as good as any 121 phazer and I definitely have a traction advantage. The tip up on mine is equivalent to ~128" track on the ground.

 

[Kkurz]

Go read the Viper forum on 137" its full of the guys looking for more transfer. Is only reason I brought it up. Its a big decision and I would feel bad if someone found out later rather than before. Like I said the new shocks and better valving help alot and a guy can always remove blocks or whole assembly so it can be fixed to personal taste. Its a new sled and none of us have rode them. Is also questions on gearing. In past 129 LE was a snocross sled=slow top end/stiffer shock valving. Havent heard gearing or driver specs yet. Next Sunday you guys will have the whole TY group at Pleasant Prairie digging into all this. Lots of questions should be cleared up I am confident in that.

Cannondale, does that mean I can take the transfer block/bar assembly right out and not chew my track up? I did in my 136" Nytro and it was the ticket. I bought the 137" for fun off trail but transfer on trail is fun!
Thanks, Kevin.