Rotating weight reduction

[Davajn]

Just out of curiosity. Could we arrange a list of tracks with their weights? Both 155's and 163's?

Id love to know the weight of the Serie 5.1 compared to the new serie 6 & 7 vs Camso 280.

Im not at all sold at the even tho they say its a lightweight track. The paddles look like they have a stiff design. But i hope im wrong.
Hard lugs = throw snow backwards = bad popup on snow.
Soft lugs = throw snow downwards = good popup on snow.

Enough said about that...
How much does porting a track do to the floatation and popup? Is it worth it just to shed more weight?

 

[Cinno]

You're all over the page here bud. You're telling me a small change doesn't matter, it's snake placebo oil and all in my head. Then you say I need a lot of snake placebos. Oh and $100 for billet drivers? WRONG!!

I was exaggerating about the $100 dollars, the reset you totally misunderstood. What color is the sky in your world?

 

[Cinno]

Cinno,
Ur calculations are correct, ur math is wrong.
20% weight reduction on the track has a huge impact on track acceleration!
Snowmobile tracks will always accelerate faster than the sled.
The amount of snow the track can grab will always weigh less than the sled, therefore the track (path of least resistance) will push the lighter load (snow) rearward at a much faster rate than moving the heavier load (sled) forward.
The load on the track varies so much due to sled angles, speed, and snow conditions, not to mention track length, lug height and design, extremely difficult to quantify!
GS6

Finally someone that gets it! I like this post! The math is correct for the given conditions I mentioned (track coupled to snow), but not correct for the SLIPPING conditions. I totally agree it is difficult to quantify. Someone mentioned the zippiness the higher tracks provide. How do we quantify that?

Cinno

 

[Indy_500]

Just out of curiosity. Could we arrange a list of tracks with their weights? Both 155's and 163's?

Id love to know the weight of the Serie 5.1 compared to the new serie 6 & 7 vs Camso 280.

Im not at all sold at the even tho they say its a lightweight track. The paddles look like they have a stiff design. But i hope im wrong.
Hard lugs = throw snow backwards = bad popup on snow.
Soft lugs = throw snow downwards = good popup on snow.

Enough said about that...
How much does porting a track do to the floatation and popup? Is it worth it just to shed more weight?

X2 I would love a sticky with every weight of every mountain track size on the market.

 

[Cinno]

Found some data on wikipedia about hydraulic coupling that may explain effects of track to snow coupling. The article mentions a formulae :

"the torque transmitting capacity of any hydrodynamic coupling can be described by the expression

r(n^{2})(d^{5}), where
r is the mass density of the fluid,
n is the impeller speed, and
d is the impeller diameter.

Maybe r is snow density?
Maybe n is differential speed between track speed and ground speed?
Maybe d is track lug height?

Food for thought. Maybe on the deep fluffy snow days when the track is slipping the rotational inertia effects are felt more. Here a low inertia track is noticeable. When the snow gets setup, or a deeper lug track is used, the slip is reduced and those effects are reduced. That zippiness goes away.

Cinno

 

[LoudHandle]

Found some data on wikipedia about hydraulic coupling that may explain effects of track to snow coupling. The article mentions a formulae :

"the torque transmitting capacity of any hydrodynamic coupling can be described by the expression

r(n^{2})(d^{5}), where
r is the mass density of the fluid,
n is the impeller speed, and
d is the impeller diameter.

Maybe r is snow density?
Maybe n is differential speed between track speed and ground speed?
Maybe d is track lug height?

Food for thought. Maybe on the deep fluffy snow days when the track is slipping the rotational inertia effects are felt more. Here a low inertia track is noticeable. When the snow gets setup, or a deeper lug track is used, the slip is reduced and those effects are reduced. That zippiness goes away.

Cinno

For an Engineer; that is a lot of "Maybe's". Even one unknown in an equation skews the results and makes them useless, let alone all of them. That's not even touching on Formula applicability.

The formula is more aimed at a torque converter for an automatic transmission, with a non-compressible fluid (as which snow, and all of it's variations, do not qualify, as it is a very compressible solid).

If the sled was strictly used for water cross it may come close to a ballpark number; if the water destiny, driver RPM, and diameter to the top of the track lug is used (as that would be your effective sheer diameter, same as the outer diameter of an impeller (tip of the blade)).

There are just too many variations in the snow pack to even get an approximation. IMO FWIW

 

[summ8rmk]

Regardless of terrain or snow conditions a lighter track will accelerate and decelerate faster than a heavier track. Generally a higher track speed equates to greater forward motion.
The deceleration will be a hindrance in hill climbs. Each load applied to the lighter track will cause a higher variance in track speed= decrease in forward propulsion. The heavier track, once at full speed will maintain a steadier speed throughout load variances.





GS6

 

[aksledjunkie]

Want to hear about anyone that is running lightweight rotating parts like titanium clutch bolts, lightweight clutch covers, etc. Does it make a noticeable difference?

The answer is yes. It does. Some notice it and others do math.

 

[ZRP Engineering]

Regardless of terrain or snow conditions a lighter track will accelerate and decelerate faster than a heavier track. Generally a higher track speed equates to greater forward motion.
The deceleration will be a hindrance in hill climbs. Each load applied to the lighter track will cause a higher variance in track speed= decrease in forward propulsion. The heavier track, once at full speed will maintain a steadier speed throughout load variances.





GS6

I disagree because every corner in a hill climb race is essentially a drag race so being able to charge into the corner faster, slow down more quickly, then accelerate out more quickly is an advantage.

 

[Cinno]

The answer is yes. It does. Some notice it and others do math.

If you read post 13 then you will realize the guy that does the math knows where to put his money and why. He does not have to waste it on components that make little difference. Cinno

 

[icr]

If you read post 13 then you will realize the guy that does the math knows where to put his money and why. He does not have to waste it on components that make little difference. Cinno

Do you still carry the 9lb high lifter jack on your sled?

 

[Cinno]

Do you still carry the 9lb high lifter jack on your sled?

Well, have we rode together?

That little attachment I gave up years ago about the time I got a RMK. Still got it tho. You want it ?

Cinno

 

[LoudHandle]

I'm not buying what Cinno is trying to convince us / sell

From an engineering perspective, the reflected inertia of all the drive train components and overall weight of the sled, back to the motor crank shaft is a function of 1/gear ratio squared. This plus the inertia of the crank and primary clutch determines the overall inertia of the sled. When the primary clutch first engages and hasn't started shifting, the sled theoretically accelerates the fastest as the reflected inertia is the lowest because the gear ratio is high. At this point about 7% of the motor torque goes to accelerating the crank and primary clutch, 1.5% goes to the secondary, 90% goes to the sled, and the other 1.5% is the other drive train components. I did this analysis by estimating the weight of all the drive train components with the weight of the sled and rider at 600 lbs. Once the primary flashes to shift speed (8000 rpm) the inertia of the crank doesn't matter anymore as it stops changing speed. So from there on 97% of acceleration of the sled is determined by the weight of the sled and rider. (and power of course)

When I first got my 2016 AXIS 800 rmk with the lighter weight crank I could definitely feel the difference in throttle response and acceleration at initial takeoff. This makes sense given my analysis. Reducing primary clutch weight like bolts and covers will make a difference in how it feels up until it starts to shift then it will be gone.

Reducing the weight of any other rotating components from the secondary to the track drivers makes almost no difference (>0.5%). From there the weight of the sled is coupled to the track as long as the track is not slipping. Therefore the rotating inertia of the track is the track plus the weight of the sled. They are not considered separate in my analysis. If you reduce the overall weight of the sled by 10% you will increase the acceleration by 10%. To get that 10% is tuff as in this example the sled and rider is 600 lbs so you have to reduce 60 lbs.

Adding 10% more power is much easier. If you can do both like burandt, then you got something.

Cinno

I'm not buying what you are selling!

There is a little validity to your steady state argument, but the way we ride these days, even that can be tossed out.
We do not ride at one speed in a straight line ever! That said; the lighter we can get the drivetrain the more responsive the sled will be, the less gyroscopic resistance we will need to overcome for cornering etc.

A light but stiff / rigid chassis also enters the equation, if for nothing else but ride predicability reasons. Sure the Doo and Yama-Cat chassis work but are squishy and unpredictable as they are not as rigid and flex too much for my liking.

It is usually cheaper and easier to raise the horse power, but that does not help to decrease the Gyroscopic effect that fights the way we ride these days. Most of the time it increases the Gyroscopic effect and makes it even harder to keep the sled playful and responsive. A turbo is just another high speed rotating element hindering changes in motion. As are superchargers, big bores, and strokers.

If your a flat lander then sure, pin it from bar to bar or however you ride.

Us mountain types are acceleration junkies and enjoy squirting from zero to 60MPH up a vertical face, and weaving thru the trees and other geographic obstacles as fast as the brain can conceive a pathway thru them.

 

[Cinno]

I'm not buying what you are selling!

There is a little validity to your steady state argument, but the way we ride these days, even that can be tossed out.
We do not ride at one speed in a straight line ever! That said; the lighter we can get the drivetrain the more responsive the sled will be, the less gyroscopic resistance we will need to overcome for cornering etc.

A light but stiff / rigid chassis also enters the equation, if for nothing else but ride predicability reasons. Sure the Doo and Yama-Cat chassis work but are squishy and unpredictable as they are not as rigid and flex too much for my liking.

It is usually cheaper and easier to raise the horse power, but that does not help to decrease the Gyroscopic effect that fights the way we ride these days. Most of the time it increases the Gyroscopic effect and makes it even harder to keep the sled playful and responsive. A turbo is just another high speed rotating element hindering changes in motion. As are superchargers, big bores, and strokers.

If your a flat lander then sure, pin it from bar to bar or however you ride.

Us mountain types are acceleration junkies and enjoy squirting from zero to 60MPH up a vertical face, and weaving thru the trees and other geographic obstacles as fast as the brain can conceive a pathway thru them.

I'm not selling any thing but science and knowledge. What steady state argument? Who said anything about a straight line? If you want to pontificate about "gyroscopic effects" go ahead but leave me out of it!

 

[LoudHandle]

I'm not selling any thing but science and knowledge. What steady state argument? Who said anything about a straight line? If you want to pontificate about "gyroscopic effects" go ahead but leave me out of it!

You claim to be an educated engineer, but you fail to grasp my one sentence parphrase of your post #13 description of the post acceleration state? "Steady State". The only place any of your claims are valid are in a straight line at a steady state. Anywhere else they are useless as we do not ride like that.


I should know better than to argue with a idiot.


I've said what I needed to.


Feel free to continue spreading misinformation under the guise of legitimate engineering and physics.

 

[Killer Time Racing]

Figures don't lie !!




But LIARS figure!!! Tell that to your boss about raise time ..

 

[Cinno]

You claim to be an educated engineer, but you fail to grasp my one sentence parphrase of your post #13 description of the post acceleration state? "Steady State". The only place any of your claims are valid are in a straight line at a steady state. Anywhere else they are useless as we do not ride like that.


I should know better than to argue with a idiot.


I've said what I needed to.


Feel free to continue spreading misinformation under the guise of legitimate engineering and physics.

So you admit "The only place any of your claims are valid are in a straight line at a steady state." and I'm also an idiot. The name calling is childish and so are your arguments because you obviously don't understand anything about rotating mass and how it effects the acceleration of a snowmobile, except maybe how it feels in the seat of your pants. Leave the math to the engineers.


Cinno

 

[tdblakes]

Really Cinno, you may have a good understanding of physics principles but you set up this problem with the wrong assumption that the track is coupled to snow and no slip is occurring. Your logic may be true if you're ripping across a lake at 60 and punch it, but not from a dead stop in deep snow.

In reality, the sled moves forward because of the amount of snow the track is propelling backward. The more snow thrown by the track, the faster the sled will move. So the faster the track accelerates, the better and more responsive the throttle will feel.

 

[summ8rmk]

How does this factor in to the equation?

GS6

 

[tdbaugha]

Just out of curiosity. Could we arrange a list of tracks with their weights? Both 155's and 163's?

Id love to know the weight of the Serie 5.1 compared to the new serie 6 & 7 vs Camso 280.

Im not at all sold at the even tho they say its a lightweight track. The paddles look like they have a stiff design. But i hope im wrong.
Hard lugs = throw snow backwards = bad popup on snow.
Soft lugs = throw snow downwards = good popup on snow.

Enough said about that...
How much does porting a track do to the floatation and popup? Is it worth it just to shed more weight?

Polaris 155 Series 5.1: 46.25lbs
Polaris 155 Series 6: 44lbs
Polaris 156 Series 7: 49lbs
Camso 156 X3: 56lbs
Camso 156 X3.2: 51lbs
Camso 156 CE 2.5: 51lbs
Camso 154 2.5 Peak: 56lbs
Camso 155 Conquer:
Camso 154 Conquer:
Arctic Cat 153 2.6 PC: 57lbs
Arctic Cat 153 3 PC: 53.8lbs


Polaris 163 Series 6: 49.5lbs
Polaris 162 Series 7: 53.1lbs
Camso 162 X3: 58lbs
Camso 162 X3.2: 54lbs
Camso 162 CE 2.5": 55lbs
Camso 162 2.5 Peak: 59lbs
Camso 162 Conquer: 45lbs
Camso 165 Conquer: 42.5lbs
Arctic Cat 162 2.6 PC: 59lbs
Arctic Cat 162 3 PC: 56.2lbs
Ski Doo 162x16x2.5: 60.2lbs
Ski Doo 162x16x3: 59lbs
Ski Doo 165 3: 49lbs