Purpose built snowbike - motor

[barefooter]

If you were going to build a purpose built snowbike, what motor would you use in it?

Not thinking a dirt bike engine... Or a Liger 625 (that is cool but ridiculous).

Street bike engine.. Snowmobile engine... What would be the best HP to weight ratio, have a decently broad powerband and still be reliable?

 

[Dam Dave]

just wishing? then a inline 600 twin with a 100 hp

 

[Sheetmetalfab]

Doo 800r works ok.

 

[Kaarlonen]

Wow!
We definitely need more info on that thing.
Looks sweet.

 

[Sheetmetalfab]

Wow!
We definitely need more info on that thing.
Looks sweet.

https://www.snowest.com/forum/showthread.php?t=376728&page=2



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[barefooter]

https://www.snowest.com/forum/showthread.php?t=376728&page=2



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Uh............ Wow. Unreal. That is outside the box

I have about a thousand questions.....

Did you ever think about fabbing a leading link front suspension like the old Ribi designs? Way stronger than a stock setuo and actually lighter... What do you think that snowbike is going to weigh all in?

 

[Kaarlonen]

Like this? Simple A-arm front suspension with hollow carbon sliders.
Also my motor of choice. Centered mass and enough power

 

[roo]

Like this? Simple A-arm front suspension with hollow carbon sliders.
Also my motor of choice. Centered mass and enough power

Now we are talking! This is a purpose built concept not centered around converting s bike into a snowmobile.
Like your way of thinking!

 

[d1100t]

Wow

Like this? Simple A-arm front suspension with hollow carbon sliders.
Also my motor of choice. Centered mass and enough power

That's amazing.
What program was that designed with?
I can see myself riding something like that.
Nice work!

 

[chumbilly1]

1000cc sportbike motor, cf chassis, integrated fuel cell!

 

[Sheetmetalfab]

Like this? Simple A-arm front suspension with hollow carbon sliders.
Also my motor of choice. Centered mass and enough power

Polaris!
Get on it!!!!


^^^^^^^^ that is what I was hoping for.........

 

[Kaarlonen]

1000cc sportbike motor, cf chassis, integrated fuel cell!

-> 1049cc yammi with boost, CVT, all cf construction, multiple fuel cells around the frame to get more volume and weight distribution like in fighter planes.
Projected weight 168kg ~ 370lbs.
Designed with Inventor.

EDIT:
Would it be ok if we talk purpose built snowmachine as a whole, not just the engine?
Something like:
*Open source purpose built snowmachine design thread*
If you could do a purpose built snowmachine how would you do it?

My point would be to get those great ideas presented elsewhere in this forum and guys behind them in same place. There are many threads about custon built bike/machines here so if we throw ideas into grinder hopefully output is pieces of blueprint for ultimate? working purpose built snowmachine. I'm sure there are more than few tinkerers here with ideas.

That picture I posted is something I've been planning since J&L Snowhawk posted his original *CVT snowbike* idea couple of years ago.
I really liked the concept and outside of the box engine placement.
That built kicked my design into gear and that is what I have now.

I have done one purpose built single ski snow machine some ten years ago, it had sled engine and CVT but it was bulky and had too many too complicated new ideas in it. Layout was about same as sleds but with only one ski. I got it running but it was more of a learning experience than working prototype.

Now I think it time for round 2.0.
Some more specs:
Track 153 3" cut down to 12" with KMH-motion 2.0 suspension (DIY) .
Yammi genesis 1049cc with MCX 270kit + CVT.
Construction CF/kevlar as much as possible.
Frame is continous optimized form of two plates with varying thickness. All mass and hi-stress points are close together and fork does not need hi-strength support because impact forces are delivered through A-arm to the center of the frame. Makes the frame small, light, stiff and strong.
Fuel is in small connected composite cells around the structure where there is leftover volume. It distributes weight around and lower that normal single tank.
Otherwise it is just normal tech arranged in new form.

 

[NEWDUCK]

Id love to try these "sno-rkt" deals with the engine behind you. There has to be a point where the engine is way to high and to far back. Put the engine inside the track

 

[Norma Stitz]

Everyone seen this extremely cool and very well documented build on BCR forum?

 

[chumbilly1]

Great ideas. Personally, an honest 100 HP would be sufficient. I don't need boost, just reliability. I keep hearing about this new powerplant KTM has developed for Adventure bike line. 800cc twin, 100HP, light and compact. And CVT creates a lot of bulk and rotating mass. I like to shift. Give me a clutch and a throttle and Im a happy boy!

 

[olymon]

Everyone seen this extremely cool and very well documented build on BCR forum?

What is the name of the build, or an actual link to it? Looks like some interesting reading to be done.

 

[roo]

What is the name of the build, or an actual link to it? Looks like some interesting reading to be done.

http://backcountryrebels.com/showthread.php?t=30436

 

[RMK935VA]

Two stroke V Twin with a snowmobile type CVT transmission. 100 to 120 horsepower. Chassis would probably have to be rigid (no swingarm pivot) to accomplish the transmission. Belt final drive like Yeti or CMX. 300 to 325 lbs. 129 or 137 track. That would be an amazing backcountry machine. I would find a way to get one if it happened before I get too damn old to do it anymore. I love my Yeti 129 and KTM 450 SXF combination but it is still a hybrid. A purpose built snow bike would be better, much better!

 

[RMK935VA]

Further elaboration on my thoughts are that the V Twin keeps it narrow, the primary/secondary are downsized a bit from what is on sleds. There is a jackshaft to allow for the final drive to be on the right side. This would keep the whole package narrow and with a balanced weight distribution. Figuring out how to route the exhaust gets a little bit problematic if the engine is a two stroke. the expansion chamber(s) is pretty bulky but a two into one like a two stroke sled should make it achievable. You also need the oil tank, fuel tank, etc. I think that a good mechanical engineer could come up with a package that will work. I would like to see Polaris work on it although I like my Yeti more than the Timbersled. However, I have not rode the new Timbersled but I have heard that it works well. I would like to see a belt final on it like the Yeti and the Polaris Axys have now.

 

[RMK935VA]

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