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2009 MXZ TNT 500SS
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Discussion Starter · #1 ·
I'm replacing a couple bent parts and getting shocks rebuilt before winter and I noticed that the front two outside idler wheels are in different positions between the two rails. It looks to be from the factory like this so there must be some reasoning behind it but I can't see the reasoning why. Personally I like symmetry hence why I added an additional stopper strap to the front arm and a fourth idler wheel to the rear axle.

So my question is can anyone smarter than me tell me the reasoning between the different positions? Or would it be wise to move them so they are in the same position? sled is a 09 500SS so I believe it is the SC-5 skid


Left rail - both idlers in rear bolt holes
Light Automotive tire Wood Gear Bumper


Right rail - both idlers in front bolt holes
Tire Automotive tire Wheel Tread Wood
 

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2009 MXZ TNT 500SS
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76 Posts
Discussion Starter · #3 ·
It keeps the harmonics down while the track is spinning...
Very interesting. I never thought of that. So basically if I'm understanding it correctly you're saying that if all the idler wheels are in the same position you could get bigger vibrations as the track moves along the skids versus having the idler wheels offset to soak up the vibrations?
 

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14SkandicWT600Ace 16MXZ900&600Ace
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599 Posts
If you want to dig into the vibration concepts further.

The distance along the rail, between the wheel center-lines, is different than the pitch of the track. So the bumps, when a bar in the track goes past a wheel, does not align with any other.

If you want to improve the "glide" further, use the DuPont hyfax. The distance the wheels protrude past the hyfax amplifies the shock when a bar in the track is pushed away by a wheel. Less distance, less bump and every fraction of a mm exponentially counts. The DuPonts wear less and, over time, keep down the "bumps".

Harmonics have the potential of building up. The example of marching soldiers needing to brake cadence when marching over a bridge is real. The shape of the attaching structures also play a part. When designing vehicles to be quiet, we tried to shape all the structures so they had constantly changing radii - in all directions - so there were as few resonating surfaces as possible. Flat surfaces, and straight bends, like a snowmobile tunnel, are the worst for noise and vibration.... And are sometimes unavoidable, which makes reducing the input that much more important.
 

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Registered
2009 MXZ TNT 500SS
Joined
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76 Posts
Discussion Starter · #6 ·
If you want to dig into the vibration concepts further.

The distance along the rail, between the wheel center-lines, is different than the pitch of the track. So the bumps, when a bar in the track goes past a wheel, does not align with any other.

If you want to improve the "glide" further, use the DuPont hyfax. The distance the wheels protrude past the hyfax amplifies the shock when a bar in the track is pushed away by a wheel. Less distance, less bump and every fraction of a mm exponentially counts. The DuPonts wear less and, over time, keep down the "bumps".

Harmonics have the potential of building up. The example of marching soldiers needing to brake cadence when marching over a bridge is real. The shape of the attaching structures also play a part. When designing vehicles to be quiet, we tried to shape all the structures so they had constantly changing radii - in all directions - so there were as few resonating surfaces as possible. Flat surfaces, and straight bends, like a snowmobile tunnel, are the worst for noise and vibration.... And are sometimes unavoidable, which makes reducing the input that much more important.
Put the DuPont hyfax on them when I first got the sled a couple years ago. I will agree they wear amazing. Definitely worth the price. I'm still amazed that harmonics play such a part as you would think that a rubber track moving along a snow covered ground it wouldn't be an issue but obviously it is. I just think it's awesome the amount of research and design that goes into all these sleds.
 

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14SkandicWT600Ace 16MXZ900&600Ace
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the amount of research and design that goes into all these sleds
Blackout. The Silent Track concept is another example of the layers and layers of technology that sleeps below the surface. The freedom within the Ski Doo organization to initiate a change in the established concept of how tracks are driven is impressive. And they executed the new concept beautifully.
 
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