Better Understanding of Todays Track Lengths

[Sledroll]

Just dont forget the approach angle. 129 vs 137 Viper the approach is much sharper bend at front of 129". Would be a interesting measurement to add to this great info. Just saying it because I do not see the difference the extra length has as being a advantage off the line in real life. Too many variables though.

I would think that the main difference the approach angle affects in a trail situation is the 137 has less friction / resistance , which allows for quicker acceleration .
My understanding is that the flatter approach angle is for off trail , to help get up on top of the snow easier .
That being said , with any decent transfer on hard acceleration the front of the track is redundant , as it is not touching the ground .
This is where the extra track length which is added to the back , comes in handy .
This is why I think the tipped up rails are real effective , as you have an extra 7.5 inches of track which to get traction with , of which is more likely on the ground , than the last 7.5 inches before the rear wheels on straight rails .
The bend point on the tipped up 144 rails , makes the sled think that is the rear axle point , and then the tipped up 7.5 inches of track digs in , where a normal length 129 , is already well on its way to a tail stand ,or in certain conditions flipping over backwards .
In the most recent CSRA season finals at HR in Barrie , which has a long up hill section , the racer , in mod class , that put on a 137 track , instead of the normal 129 , smoked the field !

Forgetting about the tipped up issue , the answer to which track to get , seems to be go a little longer than shorter for many reasons , with a sled of that has as much power as the SW .

 

[MrSled]

As long as we are talking tracks.. here is something a made a few years back on how to determine the length of track:
http://www.totallyamaha.com/snowmobiles/aaTECH/tracklength/tracklength.htm

 

[cannondale27]

I would think that the main difference the approach angle affects in a trail situation is the 137 has less friction / resistance , which allows for quicker acceleration .
My understanding is that the flatter approach angle is for off trail , to help get up on top of the snow easier .
That being said , with any decent transfer on hard acceleration the front of the track is redundant , as it is not touching the ground .
This is where the extra track length which is added to the back , comes in handy .
This is why I think the tipped up rails are real effective , as you have an extra 7.5 inches of track which to get traction with , of which is more likely on the ground , than the last 7.5 inches before the rear wheels on straight rails .
The bend point on the tipped up 144 rails , makes the sled think that is the rear axle point , and then the tipped up 7.5 inches of track digs in , where a normal length 129 , is already well on its way to a tail stand ,or in certain conditions flipping over backwards .
In the most recent CSRA season finals at HR in Barrie , which has a long up hill section , the racer , in mod class , that put on a 137 track , instead of the normal 129 , smoked the field !

Forgetting about the tipped up issue , the answer to which track to get , seems to be go a little longer than shorter for many reasons , with a sled of that has as much power as the SW .

I agree approach angle must help get on top snow and speed. Advantage 137" but in riding 137" the extra length/geometry acts like a wheelie bar. Limits transfer. This is the no1 complaint of the 137" Viper owners. Transfer=traction. The much better shocks of the 16's and hopefully new Sidewinder helps alot but many owners have gone as far as removing the transfer blocks completely. This is definitely not needed on the 129" or Obviously the 141" which is not coupled.

 

[cannondale27]

Also before anyone comes to conclusion that the 129" transfers more than 137". It used to. On Sidewinder and 17 Vipers they now put a longer front arm and center shock in them. Same as 137" so its possible the 129" for this year may NOT transfer as well as it did in past. We all will find out when we line them up on snow. Sorry for not making the decisions easier!

 

[uprider800]

Is there a reason for the longer front arm and center shock? I'm torn as to which Sidwinder to order. I just sold my boosted xf9000 and I liked the stability of the 137 but it sure was more of a hand full when ridden hard through the woods. Also when playing on the trails it just didn't transfer well. I had 230 hp and had to pull the transfer rod completely to get the front end to come up when ripping thru the trails. I'm looking to get that fun factor back on the trails and thought maybe the 129 would help in this area.

 

[cannondale27]

Is there a reason for the longer front arm and center shock? I'm torn as to which Sidwinder to order. I just sold my boosted xf9000 and I liked the stability of the 137 but it sure was more of a hand full when ridden hard through the woods. Also when playing on the trails it just didn't transfer well. I had 230 hp and had to pull the transfer rod completely to get the front end to come up when ripping thru the trails. I'm looking to get that fun factor back on the trails and thought maybe the 129 would help in this area.

I really wish I could answer that. 129" Used to in a Viper. Thats the way they have been going on the race suspension also. Better stability/Handling with less effort/fun. Same parts/Cost? I plan to map the suspension on a 129" at the TY Sidewinder intro Sunday at Pleasant Prairie,WI. But even with that still have to ride them to know. UPrider800 to me the weight in front of the 9000 in a 129" felt just like a Viper in a 137" a 129" Viper feels like a 8000 Cat front end/transfer wise. But that was 14-16 not 17.

 

[snowbeast]

Just dont forget the approach angle. 129 vs 137 Viper the approach is much sharper bend at front of 129". Would be a interesting measurement to add to this great info. Just saying it because I do not see the difference the extra length has as being a advantage off the line in real life. Too many variables though.

Cannon,i agree,but the reason I went to my 15 xtx was my dealer kept telling me,they were always 3-4 sled length ahead of there 129 cousins,and better top speed as well,and after buying the sled,and running against the 121's in our group,well its dramatic.

 

[snowbeast]

Does this mean in theory the 137" will have a better top end angle?

Yes,absolutely,this is the reason the 144 xtx beats shorter apex 121 or 128's on top.

 

[cannondale27]

Cannon,i agree,but the reason I went to my 15 xtx was my dealer kept telling me,they were always 3-4 sled length ahead of there 129 cousins,and better top speed as well,and after buying the sled,and running against the 121's in our group,well its dramatic.

Viper XTX or Apex? Big difference and I just do not see that with my Viper 129" stock or modded. Way more traction and transfer than 137". I keep posting on this subject since I truly believe that if buying the 137" for traction as a goal there will be many regrets. I cant say the 129" is better than 137" Traction and transfer wise this year because they changed it. Just keep it in mind.

 

[snowbeast]

Viper XTX or Apex? Big difference and I just do not see that with my Viper 129" stock or modded. Way more traction and transfer than 137". I keep posting on this subject since I truly believe that if buying the 137" for traction as a goal there will be many regrets. I cant say the 129" is better than 137" Traction and transfer wise this year because they changed it. Just keep it in mind.

Mine was an apex,do you feel some of the traction between the viper 129 and viper 137 could be a shock design,or transfer set up design,you rework shocks on the side correct! I feel you have more knowledge than most of us,on the quality of shocks and shock valving vrs crappy shocks and or there valving quality,the apex xtx was a fast sled on top and it was also quick off the line,but its shock valving and transfer was way off,IMO.

 

[MrSled]

Mine was an apex,do you feel some of the traction between the viper 129 and viper 137 could be a shock design,or transfer set up design,you rework shocks on the side correct! I feel you have more knowledge than most of us,on the quality of shocks and shock valving vrs crappy shocks and or there valving quality,the apex xtx was a fast sled on top and it was also quick off the line,but its shock valving and transfer was way off,IMO.

Apex to Viper 129 to 144..not even close comparison..

 

[Motorhead]

Lot's of neat info on the changed identity of, and a bit of current history of (track lenght vs footprint).

I suspect that my new SW LTX-LE 137 when compared to the 129, will push a bit more in the corners, will hook up a bit better, may or may not be as fast or faster on top end, will work better on stutter bumps but maybe not on bigger bumps, but for sure that 137" track in that 141" chassis looks best to me. Just plain looks mean. Ha Ha

 

[cannondale27]

Mine was an apex,do you feel some of the traction between the viper 129 and viper 137 could be a shock design,or transfer set up design,you rework shocks on the side correct! I feel you have more knowledge than most of us,on the quality of shocks and shock valving vrs crappy shocks and or there valving quality,the apex xtx was a fast sled on top and it was also quick off the line,but its shock valving and transfer was way off,IMO.

Forget about the Apex as far as comparison. The Viper is totally different and Sidewinder will also be totally different. Its the same shocks on both 129 RTX and 137 LTX Viper except for length. Valving on both did help transfer but even with the best of shocks the 137 Does not have the Potential transfer potential as the 129 unless you start going past factory settings on transfer blocks. Front end always feels heavier than 129".

 

[stevewithOCD]

You guys are KILLIN" me! If the 137 doesn't transfer as well as 129 & doesn't hook up as well, why would i buy it? I WAS ordering tomorrow, but i'll hold off couple days until someone yells at me. These are the times i need a girlfriend to tell me what to do...

 

[cannondale27]

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.