Mountain Sled Geometry

[mareshow]

Here is one of an 2009, I can't decide if the steering post angle is the same as the XM or not. I know in the launch they said they pushed it forward more, but did they just push it forward more in the chassis and keep the same angle?

Haha, it’s the best I can do with Paint.

I think you and I are saying the same thing. I don't disagree that the angle of the running boards help you to create leverage over the bars. However I believe the closer the steering post angle is to being parallel with your body the easier it is to "roll the sled up".

if you make the sled naked its more like this.

By these pictures, one could argue that it makes the Sled easier to pivot and turn because the length of the fulcrum is almost 1.5 x longer as well as the attack Angle is also quite more acute making it easier again.

 

[dogsmack]

Seriously!!! Just get on the damn thing and ride, adjust what bugs you.....repeat.

 

[adamg]

The sidehill washout theory interests me. My theory is that the XM, being wider in the bodywork and forward boards, plows more snow up front. The extra force required to plow this extra snow comes from the forward traction of the track. Tracks in powder generate traction by throwing powder that was under the track behind the track at speed, and the subsequent momentum gained from this. As a side-effect of generating that forward traction they displace more powder from under the track. So, to push the extra snow the track has to bury a little deeper down. At some point the snow plow drag requires so much track burying that the track ends up lower on the hill than the skis, and at that point it washes out / points uphill.

 

[takethebounce]

So what about previous M series sleds? Can't get much wider than that. Not to much issue in technical terrain there.

You are reading into something way too much.

You haven't even looked at what the front suspension is doing.

sent from a top secret location

 

[CUSO]

I think this new "washout" term is a theory of someone who can't position himself properly. I mean you can use all the theories known to man (or woman.. LOL) but the only thing I can think of is the 15 wide digs a deeper so called rut and holds with side pressure?

The sidehill washout theory interests me. My theory is that the XM, being wider in the bodywork and forward boards, plows more snow up front. The extra force required to plow this extra snow comes from the forward traction of the track. Tracks in powder generate traction by throwing powder that was under the track behind the track at speed, and the subsequent momentum gained from this. As a side-effect of generating that forward traction they displace more powder from under the track. So, to push the extra snow the track has to bury a little deeper down. At some point the snow plow drag requires so much track burying that the track ends up lower on the hill than the skis, and at that point it washes out / points uphill.

 

[Trax 2 Treadz]

Ask the guys who frequent the Yamaha section of this forum I have talked endlessly about sled geometry and back to front balance.........

Jan

 

[Pwdrh0r]

Preference preference boys.. Take it to the hill. I'm pretty sure crazy Canadian had a post about this already. You can adjust to any sled.

 

[pistoncontracting]

Call it geometry, physics, whatever you want. At the end of the day a Pro can sit on it's edge, on it's own. In fact, it will even 'sway' side to side an inch or two depending how much fuel is in the tank.


For the life of me, I can not get my XP, with or with out the s-36 to do this. I could not get my '10 Nytro to do this even after the z-broz front end was installed. And although I do not have access to an XM, I'm willing to bet they can't do this either.

 

[snopro]

Call it geometry, physics, whatever you want. At the end of the day a Pro can sit on it's edge, on it's own. In fact, it will even 'sway' side to side an inch or two depending how much fuel is in the tank.
View attachment 151913

For the life of me, I can not get my XP, with or with out the s-36 to do this. I could not get my '10 Nytro to do this even after the z-broz front end was installed. And although I do not have access to an XM, I'm willing to bet they can't do this either.

There is a pic of an XM dooing this somewhere on this site. Your a little late....

 

[maxwell]

Call it geometry, physics, whatever you want. At the end of the day a Pro can sit on it's edge, on it's own. In fact, it will even 'sway' side to side an inch or two depending how much fuel is in the tank.
View attachment 151913

For the life of me, I can not get my XP, with or with out the s-36 to do this. I could not get my '10 Nytro to do this even after the z-broz front end was installed. And although I do not have access to an XM, I'm willing to bet they can't do this either.

an xm can certainly do this nooo problem. theres eveen a few photos kicking around here. but even so....what is that really proving besides a unique photo....nothing.

 

[pistoncontracting]

an xm can certainly do this nooo problem. theres eveen a few photos kicking around here. but even so....what is that really proving besides a unique photo....nothing.

I'd like to see the photo. Even better, I'd like to watch someone do it, to see how easily it does it. I'm willing to bet a track with no outer support does not act like this.

If you can get a machine to do this without any forward motion, it should be some indication how it will respond while riding it.

 

[snopro]

Search it out. Like we said its there for you to see on the site.

 

[zed899]

 

[snopro]

View attachment 151931

Thank you Zed!

 

[pistoncontracting]

View attachment 151931

Thanks for finding it. My search skills could use some work.

I guess I was wrong about the XM. The pic just proves exactly why the Pro can hold a line, and the XM requires more effort.

You'll notice the Pro is in a perfect counter steer position. I hate to sound 'text booky', but Rassmussen says that to be in control of a snowmobile, it needs to be on edge. In order to establish and maintain that edge, you must counter steer.

Now look at the pics. The Pro is in a counter steer, the XM... not so much.

I'm not bashing Doo. I like my XP. I love my Olympic. I take no enjoyment that my Pro requires no effort to hold a line. But at the end of the day, you can not argue the fact.... the Pro chassis just plain works.

 

[snopro]

Huh?? I think a sled that can hold a line without any countersteer is a better balanced sled. If you gave the Doo countersteer there it probably would fall over. Now that is a sled that I want to ride.

 

[maxwell]

View attachment 151933

Thanks for finding it. My search skills could use some work.

I guess I was wrong about the XM. The pic just proves exactly why the Pro can hold a line, and the XM requires more effort.

You'll notice the Pro is in a perfect counter steer position. I hate to sound 'text booky', but Rassmussen says that to be in control of a snowmobile, it needs to be on edge. In order to establish and maintain that edge, you must counter steer.

Now look at the pics. The Pro is in a counter steer, the XM... not so much.

I'm not bashing Doo. I like my XP. I love my Olympic. I take no enjoyment that my Pro requires no effort to hold a line. But at the end of the day, you can not argue the fact.... the Pro chassis just plain works.

This is funny. Because tipping yor sled on edge in Saskatchewan sure shows what it's gona do on the hill in deep snow LMFAO

 

[pistoncontracting]

Huh?? I think a sled that can hold a line without any countersteer is a better balanced sled. If you gave the Doo countersteer there it probably would fall over. Now that is a sled that I want to ride.

Thats right... it WOULD fall over.

The trouble is though, it would fall to 'right' itself, pulling the ski's and track down. This would require MORE effort to even maintain once you DOO get on edge. So instead of focusing on forward momentum, more effort both physically and mentally is wasted on maintaining balance.

And yes, holding a line WITHOUT counter-steer would be nice, but you need counter steer to balance yourself...

This is funny. Because tipping yor sled on edge in Saskatchewan sure shows what it's gona do on the hill in deep snow LMFAO

It's alright Max, I don't like it any more then you do. I curse out loud every time I get on this Pro...

But again, it's not a matter of opinion. No matter how strong of emotion you have.... if a sled will handle like this on hard, packed, shitty snow... just imagine what it will do in powder.

BTW... it says your from Sherwood Park... did you guys build the mountains recently, or did I just miss them last time I went through??

 

[BeachSled]

Call it geometry, physics, whatever you want. At the end of the day a Pro can sit on it's edge, on it's own. In fact, it will even 'sway' side to side an inch or two depending how much fuel is in the tank.
View attachment 151913

For the life of me, I can not get my XP, with or with out the s-36 to do this. I could not get my '10 Nytro to do this even after the z-broz front end was installed. And although I do not have access to an XM, I'm willing to bet they can't do this either.

Why not go set that sled on the flat ground and take a pic of it. You have it all setup in a rut, and what is this proving ? That the sled needs to be almost on its side to balance ? Nice pick but not really proving anything !

 

[Sask Sledder]

I can drive my XM around on one ski just like i used to do with my Honda trike. Steering both ways. And i can do it with each foot planted on respective running boards. No wrong foot.

If thats any indication.

And once in a sidehill the sweet spot is huge and it doesnt want to right itself at all.

The XM is very different in feel to the XP so if you havent driven one shut up.