HERE'S WHAT I'D LIKE TO SEE... THE 2016 XTD.... Xtreme Terrain Dominator

mountainhorse said:

Save the widetracks for different terrain...This thing, if pulled off, would go places that Burandt couldn't go on a regular machine.

A tall lugged, lightweight machine, IMO... wouldn't have any issue getting around int he deep.



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^^^^^^^
Exactly.
That other terrain is called J hooks on the hill and wide open spaces.
Meadow munching water buffalo's.

Skinny and nimble is the only way.

Just to re-bump this - with regards to a narrower track;

We have been talking about tire sizes vs traction extensively on an auto forum. Guys have done extensive testing on very high HP cars (like spin drag radials at over 100mph type cars). Every time the consensus is the same, and completely contrary to what most would think - for a given model of tire, the height/circumference of the tire has notably MORE effect on traction than the width. If you have 2 tire choices, say 315 width by 27" tall, vs - 295 width x 28" - the taller, skinnier tire has much more traction due to its longer contact patch. Now, is there a small sidewall flex consideration? Yes. Also, a small gear ratio change, be we are talking cars that could spin any ratio within a reasonable range with ease.

I think there's at least some translation to our sled applications. As we discussed in this thread - given the track lengths, lug designs, lug lengths and track compounds available today - I think you could use a narrower track without giving up any notable traction. Particularly given that Pol has a great rear suspension design, and will likely keep pushing the weight reduction envelope.

So it seems that the width at the primary clutch point may be the most restrictive - no? Also, perhaps narrowing the front end more, while maintaining good suspension geometry/shock lengths. Thoughts?

Well a v motor would narrow up things a lot. But that would be a big jump for a manufacturer to make.

Good call....wonder if a 2-cyl V motor would be balanced enough to handle the type of ouput and loads seen in a sled? There are some sport bikes out there making decent power out of a V-twin, but the high-rpm load in a sled would be on another level, and the weight would have to be way down. Like you say - big engineering project, as I can't think of a 160hp 2-stroke V-twin ever having been done.

Who's going to buy one and cut it in half?

http://www.aaenperformance.com/V4_racing_engine.asp

Wasn't Fastrax testing a single cylinder with a turbo?

That is one possibility, another is to use the current inline twin design and relocate the whole CVT to inside the drivers. As the current crankcase is 12 1/2" wide, it would allow the sled / bike to be a full 3+ inches narrower. The Engine centered in the chassis and the only things protruding would be the recoil housing and the Gates Poly-Chain Carbon belt drive off the crankshaft on the other side. Poly-Chain from crankshaft to driveshaft centerline. A bit harder to tune perhaps, but the lines would be clean and efficient, nothing to catch on the snow other than foot pegs essentially.


My thoughts are the next thing to help move the light-weight / performance evolution of the sleds / bikes is to improve the drivetrain and lose the heavy inefficient clutches that really have not changed since the '60's (sure they have been tweaked a lot over the years, better materials and geometry, but nothing revolutionary). If they were to incorporate the CVT with the final drive ratio. The total weight from crank shaft to track could be well under 15 pounds. Total machine weight could be down to near moto-cross bike weights, sub-300#'s dry easily.

Wellllllllp

Whatever it is,,,,, or, will be,,, I'm gonna get one and RIDE THE PI$$ OUT OF IT!!!!!!:becky:

I would think the width of track needed would be defined by the weight it needs to propel and float. A lighter sled would need less horse power thus being able to use a smaller lighter engine to get the same results. There has to be a balancing point somewhere where the "feel" of the sled is sacrificed for the gain of lighter weight.

I think we need to advance in the area of the pipe as well... something that doesn't wrap as far over the sled and take up so much under hood space... need to figure out a way to center the motor, make it narrower, perhaps tunnel dump or dump exhaust out of the front middle of the sled? Less pipe is less space under hood. The flotation of the sled comes from the track, get the rest of the sled out of the snow and reduce the drag.

Just like we saw back in the 90's when in deep snow the phazer was solid. Didn't climb well cause it was down on power, but got up on top of the snow and plowed along well for what it was compared to XLT's and Powder Specials cause it was light weight!

We are seeing a lot of these same things on Chris' sled with his airlock running boards! This is something we attempted back in the day with larger drop brackets on sleds to get the skid out of the tunnel and help prevent the running boards from dragging. I don't see a single draw back to narrower sleds with a narrow track with large paddles. Snow drag and weight are the enemies. Great topic and love that the sport is continually evolving.

Jay, traction and floatation are 2 different things. Sleds need both and cars need one. Lack of floatation is why there is a point that traction increases as you skinny up on your tire and circumference is added time to cool the rubber.

If you have a 6"tall lug 13" wide 153 you have all the traction but little floatation. You leave the parking lot and have to hop off the trail up to get something the 6"s can bite on instead of fold and squirm.
Then you keep the track speed up as the snow deepens to propel forward instead of sink because floatation is gone but sooner or later you need to slow down and make a maneuver unless you are on the prairies.
There is a balance that sleds need in floatation and traction. Before todays tall lug tracks people who wanted floatation had to use a long short lug utility track to convert. they had an advantage on a fresh dump day (more floatation needed) of sitting on top of the snow but when it settled (less floatation needed) they lost their advantage to shorter deeper lug tracks because of traction.

Boondocking in the deep with a skinny track sucks (IMO) unless there is enough weight reduction to equal the loss in floatation. Slow down to turn up in a tree well and you better wick up the trackspeed to 70 mph pretty quick or you will sink until you are spitting out pine needles. They have been around here before.
Early Firecat conversions were thrown away after the 15" wide M7's came out. Those M7's were heavier too.
Mountain somebody built a skinny lightweight high HP custom with a skinnyed up long tall lug track a long time ago. Everybody ohhed and awed of how easy to side hill and asked is this the future? Where is that concept today? It's not gone because there is no one to spend the money on the build, that is forsure lol.

For any OEM to build and equal to present model boondocker with less floatation (skinny track) would require equal weight loss in the machine when you add the complete on the snow weight. Meaning, 25% loss in floatation (say you go from 16 wide to 12 for the easy math) for a 750 lb package (rider, sled, fuel, snow, stuff,,, if you are skinny lol), and the total weight you need to remove from the current model is roughly 187.5 LBS!! Unless, we start to operate the sleds via video feed and remote control.
Have you tried to remove and honest 50 lbs? That's why we have 174"x 3" and not 141 by 8" today. 'Cause floatation boondocks easier and Mcdonalds isn't going away.

The sled bike and Hawk are a market of their own and some OEM might want to join in but no way no how (IMO lol) is a sled with substantially less floatation going where a present day sled can go with a good rider.

"Lest We Forget" for Canucks today.

Good call on traction vs floatation. And even with the car tire, there is a point of diminishing returns, and a point of going backwards. Obviously a bike tire on a car won't get much traction no matter how tall it is. But in the case of an extra inch of height vs an inch of tire width, the height (track length) wins out.

So, like you say, given appropriate weight reduction, suspension setup, track design, etc, I believe it is not far fetched to expect equal traction and floatation (to what we have now), with more agility via a narrower track. Some of the weight reduction would actually be part and partial TO the track (narrower track = narrower bodywork = narrower skid = everything lighter), I believe it is not that far fetched. Obviously there is going to be a point where weight can't reduce much more, and where the narrower track is unable to maintain the same floatation - but I don't think the 15" wide is the tipping point with all the new tech from the past 5 ish years.

I've owned and ridden 16", 15" and 13" as well as 136 141 144,,,. Each has a advantages and disadvantages with the traction- floatation ratio in snowmobiling.

You want a whip it sled, put a 144x 16x 3.25" on a turbo 2 stroke. You want to tow your friends out on fresh dump day, take a 159x 20x 1.25 with a fan motor.
Extremes but both will take you anywhere. One does it a 10 mph and one does it 60 mph. 10 mph travel speed takes less skill than 60mph travel speed. Somewhere in the middle is where the OEMs have to target IMO.

There may be something very new from Poo next year or the following but I think they will make a sub 400 lb 160 hp machine (what a spring splash that would make) so easily with what they have already. It would leave room for the carrots on a stick for 4 yrs too and finishing with 370 lb and more carbon sheets for the movies.
The AXYS did not change the wheel. It just improved it again.

Snow bikes and Hawks are really neat but they aren't sleds. Poo may attempt or risk making that market grow. I'd like to try one but I'll keep the sled too.

I know that this same time last year Polaris Ind. bought two Husaberg FE501 dirt bikes, one with the Mountain Horse ST and one with the Mountain Horse LT. All for their private testing.
Is Polaris trying to enter the one ski market, I have got to believe that they are considering it. their R&D on a one ski has got to lead to some innovative thoughts on how to improve the current layout of the RMK.

Thanks Scott!!!!! The lords adhesive I was sniffin last night is finally wearing off.

My vote is read this closely. It might be exactly what we will see tomorrow. Eric got it right on the 15'

Scott said:

4 years later, it's fun reading through this thread again.

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Do you know something we don’t? Seems sort of fishy.