so whats your point ,its a very cool, inspiring machine ,your point is you dont agree or like it or what the builder is wasteing his time ,or what that its very existance offends you ,it is a person that craps on others efforts and energy if they have no understanding that is a real joke,why dont you try to write somthing positive or at least NOT ignorant .I would rather look at the dudes mini sled than your mind pollution...or just keep posting so one can fully understand the basis for your almightyness you feel obliged to share with the common folk..
Is a 200 lb dry sled possible?
- Thread starter AKrider
- Start date
so whats your point ,its a very cool, inspiring machine ,your point is you dont agree or like it or what the builder is wasteing his time ,or what that its very existance offends you ,it is a person that craps on others efforts and energy if they have no understanding that is a real joke,why dont you try to write somthing positive or at least NOT ignorant .I would rather look at the dudes mini sled than your mind pollution...or just keep posting so one can fully understand the basis for your almightyness you feel obliged to share with the common folk..
S
sledfreak89
Well-known member
A Lamborghini is just as ridiculous as this in your perspective. I bet you wouldn't be complaining about who built it, and im sure you would definitely drive that! Think about it....
less than 200lbs
Found one
http://www.made-in-china.com/showro...-Snow-Scooter-302-80CC-CE-EPA-Snowmobile.html
oh, that's not what you meant.
Found one
http://www.made-in-china.com/showro...-Snow-Scooter-302-80CC-CE-EPA-Snowmobile.html
oh, that's not what you meant.
Wow. So much love and hate. Must be something we care about.
The snow scoot sorta sets the bar...1/2 size sled, 220 lbs. The skandic tundra 300 comes in at 380 lbs...must be possible to do better than that.
A lot of weight, in any vehicle is in the bodywork. Stressed engine case, stressed fuel tank/seat, maybe even stressed can/pipe? I like nikoli's idea of steering post over the front. Use a single a-arm and shock/strut front suspension, and maybe swingarm rear with single float? Diamond drive is light, but I think a belt would be lighter. No jackshaft...just drop from the secondary to the driveshaft.
I like the cat 570 fan...70HP, and pine motor sports (Idaho?) had a 630cc big bore. Aaen makes a pipe...call it 80hp?
less is more...in spite of my sig line.
John
The snow scoot sorta sets the bar...1/2 size sled, 220 lbs. The skandic tundra 300 comes in at 380 lbs...must be possible to do better than that.
A lot of weight, in any vehicle is in the bodywork. Stressed engine case, stressed fuel tank/seat, maybe even stressed can/pipe? I like nikoli's idea of steering post over the front. Use a single a-arm and shock/strut front suspension, and maybe swingarm rear with single float? Diamond drive is light, but I think a belt would be lighter. No jackshaft...just drop from the secondary to the driveshaft.
I like the cat 570 fan...70HP, and pine motor sports (Idaho?) had a 630cc big bore. Aaen makes a pipe...call it 80hp?
less is more...in spite of my sig line.
John
F
Flange
Well-known member
The thing was truely ahead of its time.
i have to agree, i find myself having a blast riding my daughters indy 500.
Here ya go. 250#'s http://www.bullheadmoto.com/Super_Mod_Scoot.html
I think one thing to keep in mind with light weight isn't the dry weight. It is the weight of sled after you have ridden it for 10-15miles hopped off trail a few times and let the skid fill with snow, slush to form along running boards and under tunnel.
If you have ever looked at a aircooled sled it has way less slush build up and that is because there isn't hot water to get the snow to melt and stick to the sled. When my full grown sled is loaded with slush I bet it adds 30-40# over the whole thing.
I think air cooled will have a big advantage over liquids in real world weight not dry in the shop.
Engineering wise if you could get by with a small radiator instead of the typical arrangement of heat exhchangers then there could be hope for the higher HP of a liquid but you would need a fan at times.
You guys have me thinking that I think you could get a long ways with cr-mo rear tube chassis that look like the hardwood sled, no track coverage back of seat, very simple front suspension - think macpherson strut type arrangement inplace of leafs for a bit more travel.
Motorwise - because I am a big guy I would probably want 600cc
but for ideal setup a 440 for your more typical 180# guy would be the better deal.
Rear skid - probably going to take a hit on comfort but travel will probably have to be 6ish inches so you don't need as much hardware there.
Great - now I need to start browsing swap meet.
If you have ever looked at a aircooled sled it has way less slush build up and that is because there isn't hot water to get the snow to melt and stick to the sled. When my full grown sled is loaded with slush I bet it adds 30-40# over the whole thing.
I think air cooled will have a big advantage over liquids in real world weight not dry in the shop.
Engineering wise if you could get by with a small radiator instead of the typical arrangement of heat exhchangers then there could be hope for the higher HP of a liquid but you would need a fan at times.
You guys have me thinking that I think you could get a long ways with cr-mo rear tube chassis that look like the hardwood sled, no track coverage back of seat, very simple front suspension - think macpherson strut type arrangement inplace of leafs for a bit more travel.
Motorwise - because I am a big guy I would probably want 600cc
but for ideal setup a 440 for your more typical 180# guy would be the better deal.
Rear skid - probably going to take a hit on comfort but travel will probably have to be 6ish inches so you don't need as much hardware there.
Great - now I need to start browsing swap meet.
Excellent points! If free air didn't prove to be workable, a small liquid cooled engine with a radiator makes good sense. The cooling system would be more compact and lighter. It could even be more protected from damage than heat exchangers.
Probably not...melting snow can absorb amazing amounts of heat...thereby making the cooler size much smaller. I'd guess the radiator size on a liquid cooled sled would be the size of the radiator on a 1000cc bike at least. It would have to have clean, cool airflow, and probably a fan also...more weight.
Lightweight priority=fan cooled. HP priority=liquid cooled. You could use the coolers and lines in the structure, though...but you still have to carry around the coolant.
That has been my thought for some time. Tube chassi with cooling going through the tubes, maybe add a little more tubing for the cooling but then no additional cooler. Tubes go all the way to the motor = hardly any hose filled with water.
RS
Heat Exchanger on sled is basically a liquid to liquid exchange once the slush is built up which as noted is very effective transfer of heat.
But if you found a radiator out of something that makes similar (or slightly less) HP then you could probably make it work. Reason I say less is that sleds are running at 50F or less, most other 'toys' that you might borrow parts from work at lots warmer temps and the cooling package gets designed for 120F days. HP is the key to compare not engine size as much.
If you take a massive load of powder over the thing and block air flow it then starts working as a liquid to liquid exchanger.
If you just tried to use the tube structure you would need to use aluminum to help with heat transfer, and would be a real trick to get a flow path that is balanced enough to work. If you found the right profile tube sections it probably could work fairly well with only a few places where you may want to add in cooling fins.
Moving coolant is much easier than moving the air volume required so to cut down on your parasitic loads you almost need to be either a free air or go electric for the cooling fan and possibly boost the electrical system with a battery to handle periods where fan is sucking more juice than system charges. Monitoring head temps would be key to keeping from cooking the thing.
When your stuck all the power to weight in the world doesnt mean a thing. A 300# or so sled with say an 860 smallblock on carbs, or a 780 cat sno-x motor, and all the Ti and Carbon fiber goodies you can get would be a the funnest sled to ride, as well as not make all your buddies pretend they didn't see you when you get stuck.
But don't sled 2 strokes need cooler coolant than most other engines, typically running 120-150 deg F? This would increase radiator size.
Gonna disagree here, too, slightly. While aluminum is around 5 times better at transfering heat than steel, the temp. difference across the tubing (ID to OD) should still be less than 1 degree. Should transfer fine. If they have fins, they should be alum. Balancing flows could be a prob. I think edge coolers are a great idea. A set of tubes at tunnel corners and edges would need very little else, especially if welded or formed into the tunnel (speaking of alum. here again).
John
Back when I first started riding we had a TX 250 and a TXC 340 free air sleds. The issue I disliked the most about them was due to the big opening in the cowling that let in both the cooling air but also snow that got on the clutches and made the belt slip.
I like the idea of free air because it is simple, but I also remember how egg frying hot those sleds got in the spring. I love fan cooled sleds but I've also burned one down during some spring riding.
I've never understood why cars, trucks, motorcycles and quads all get by just fine with radiators but they are not commonly used on sleds? I would think weight could actually be saved running a radiator rather than traditional heat exchangers. The radiator shouldn't need to be as large as one on a summer toy plus it would need less plumbing because it could be mounted right next to the engine at the front of the machine. Actual running weight of the sled should decrease since melted snow and ice wouldn't be created inside the tunnel or on the floor boards. The added benefit would be a sled that could actually be run in low snow conditions without worry about insufficient cooling. An electric fan would be a good idea.
So, you figure a radiator that is made of aluminum and with far less rubber hose plumbing and likely a reduction in coolant will probably still be lighter or at least the same as a conventual system even with an electric fan.
I like the idea of free air because it is simple, but I also remember how egg frying hot those sleds got in the spring. I love fan cooled sleds but I've also burned one down during some spring riding.
I've never understood why cars, trucks, motorcycles and quads all get by just fine with radiators but they are not commonly used on sleds? I would think weight could actually be saved running a radiator rather than traditional heat exchangers. The radiator shouldn't need to be as large as one on a summer toy plus it would need less plumbing because it could be mounted right next to the engine at the front of the machine. Actual running weight of the sled should decrease since melted snow and ice wouldn't be created inside the tunnel or on the floor boards. The added benefit would be a sled that could actually be run in low snow conditions without worry about insufficient cooling. An electric fan would be a good idea.
So, you figure a radiator that is made of aluminum and with far less rubber hose plumbing and likely a reduction in coolant will probably still be lighter or at least the same as a conventual system even with an electric fan.
Negative, it would need to be much larger for a couple of reasons..
1) The average speed on a snowmobile is quite low in comparison to a bike. Low speed = low thermal exchange = overheated engine.
2) The average duty cycle of a snowmobile is much higher then that of a motorcycle. I ride my sled WOT quite a bit. I don't know many people that do that on the road unless they are on a race course, but then again, they are probably going 100+ too...
3) I tried it, it doesn't work. As said before, heat exchangers are much more efficient then radiators...
The only benefit a radiator would have is under no snow conditions, but then, who really cares about that?
E
extremsledder
New member
i like the idea of a fan cooled light weight play sled as i have a sno jet that i have bean slowly working on as it sits it seams to be very light weight. it has a 141x3/4x15 track with 4 holes ported in it, my plan for a motor is a yamaha exciter 440 fan cooled motor with 60 over yamaha phazer cylinders on it with a mild port job and a set of twin pipes or just a single iam undecided i will probly try both setup's. as for weight the sno jet is light because of the chain case being only on the one side so no jack shaft for the clutch. my plan is to keep it to the bare minimum it will be premix fuel, no tail light, a driving light for a head light, no speedo just a tach, as for a seat it will probly be a dirt bike seat with a aluminum frame. u also have to think that being old it has cable pull brake not hydrolic so you have less weight with the cable and because its not a high hores sled the cable brakes are fine just stuff like that adds up, i have had to change the belly pan which is aluminum and it had all steel rivitis which got changed out for all aluminum ones so it should be a fun little sled when its running, sure it wont be a power house but for around the yard and the neigbour hood it will be fun
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