SC10/SC10-2 Performance Modifications to Reduce Track Drag

SC10 Suspensions

Mar. 01, 2000 By Steven LaMunion
If you have a Ski-Doo snowmobile with an SC10 skid (96-99 models) you may have noticed that there are specific areas on the hyfax that wear, while other spots show virtually no wear at all. The wear regions are pretty consistent through all models and years.
Photo 1
Photo 1
Photo 1 shows a skid from a 1999 Mach 1 set up on a workbench. There is a straightedge placed under the hyfax, with the two front outside wheels removed for clarity. You can see that the hyfax is hardly worn directly under the points where the wheels contact the track. The wear spots are in front of the wheels, between them, and the worst spot is behind the front wheels. There is also a minor wear spot just in front of the rear 165mm wheel (not shown in picture).

 

The track is constantly dragging on (and wearing out) the hyfax. If you have a 98 or 99 model sled with the closed window track then your hyfax wear can be extreme under certain conditions. The coefficient of friction between the hyfax and the rubber track is greater than between the hyfax and the metal clips. Does the closed window track keep more snow on the hyfax for lubrication? That's the theory and it looks good on paper. However, what if you're a lake runner and you spend the day blasting across the ice where there is little or no snow for lubrication? What if you live in upstate NY, as I do, and you find yourself putting road miles on your sled, or running trails that are more frozen dirt than they are snow? These are the conditions that do not provide ample lubrication for the hyfax. Consider that the "drag" created is robbing horsepower. Have you ever smelled burning plastic when you're riding your sled? Do you occasionally feel the track clips stick to a hot, soft hyfax when you come to a stop? Are you a lake racer that does not want the power robbing drag on your hyfax?

New hyfax is cheap and easy to install. However, a new hyfax actually drags more than a worn out one. Even the super slippery space age material hyfax creates a drag, maybe not as much as the stock hyfax, but it's still there.

Photo 2
Photo 2
The only way to eliminate the drag is to add more wheels to the skid. What do you put on the skid and where do they go? Photo 2 shows all the OEM parts that are needed to put additional wheels on the skid. The parts will vary slightly depending on the vintage of you SC10. 99s use plastic idler wheels where 96-98 use aluminum. The wheels on the outside of the rail use a spacer that is not used on wheels inside the rail. The skids with the plastic wheels use a shield and a cap over the wheel to protect the bearing from foreign material. Parts list per wheel to be added:

For 1996 - 1998 Aluminum Wheels:

 

 

 

MSRP

Qty

PN

Name

Application notes:

$4.04

1

503174600

Support

 

$0.30

1

207182544

Bolt

 

$0.59

1

207088044

Bolt

 

$0.43

2

233281414

Flange Nut

 

$0.55

1

503183100

Washer

 

$0.55

1

503173700

Washer

Use on wheels on outside of rail only.

$24.83

1

135mm Alum wheel, w/6205 brg, circlip (for 96-98 aluminum wheel)

$31.72

TOTAL MSRP

For 1999 - 2000 Plastic Wheels:

 

MSRP

Qty

PN

Name

Application notes:

$4.04

1

503174600

Support

 

$0.30

1

207182544

Bolt

 

$0.59

1

207088044

Bolt

 

$0.43

2

233281414

Flange Nut

 

$0.55

1

503183100

Washer

 

$0.55

1

503173700

Washer

Use on wheels on outside of rail only.

$1.23

1

572089000

Shield

 

$2.47

 

570063600

Cap

 

$19.68

1

135mm plastic wheel, w/6205 brg, circlip (for 99-00 plastic wheel)

$30.27

TOTAL MSRP

The prices above are the manufacturer's suggested retail price for OEM parts. Ingles Performance Ski-Doo, Phoenix, NY (1-888-2INGLES) offers these wheel kits for a reduced rate:

-PN 900-0053-01 for 96-98 aluminum wheels for $27.95
-PN: 900-0053-01 for 99 plastic wheels for $ $26.95
-PN: 900-0052-00 for a hardware only kit (no wheel) for $15.28
(Please specify color when ordering.)
Photo 3
Photo 3

For the SC10, you can add up to four additional wheels at the front of the skid. The first step is to remove the existing stock wheels in the front of the skid. There are a total of six wheels (three on each rail). For the inner wheels, remove the support from the rail. Move the support forward on the rail until it is centered between the two "windows" in the slide rail (see photo 3). Use a center punch and the support as a guide to mark holes to be drilled for the support. Drill two new mounting holes using a 5/16 (or 8mm) drill bit. Re-install the inner wheel in this new location. Remember, on the inner wheels, PN 503173700 washer is not used in the assembly.

You can now install a new wheel/support assembly on the OUTSIDE of the rail in the location where the inner one was originally located.

Photo 4
Photo 4
(A word of caution here, if you're banging your sled hard all the time to where the rear suspension bottoms fully, the arm of the torsion spring MAY come in contact with the wheel support. If you are concerned that this condition may occur on your machine, you can leave the outside support and wheel off. To check for clearance, remove the wheel (leave the support on the rail), load the sled with all your friends to squash the suspension down to the bump stops. Visually check to see if the torsion spring arm contacts the wheel support.)

Re-install the OEM outer wheel that is forward of the coil spring support bushing. Using a new support, place it as far forward on the inside of the rail as you can while still keeping the support fully against the slide rail (see photo 4).

Photo 5
Photo 5
Use a center punch and the support as a guide to mark holes to be drilled for the support. Drill two new mounting holes using a 5/16 (or 8mm) drill bit. Install the inner wheel in this new location. (Remember, on the inner wheels PN 503173700 washer is not used in the assembly.) The last step is to re-install the front outer wheel. It should look like photo 5 when complete.

Note: On 1997 models you may want to substitute the 141mm wheels for the front inner wheels. These skids had a particular problem with excessive wear at the front of the skid.

SC10-2 Suspensions

It appears that Bombardier put some thought into the SC10-2 with regards to hyfax wear and the drag of the closed window track. Take a look at all the SC10-2 sleds at the grass drags and you'll see that most of them have added up to six 135mm wheels to the skid. While Bombardier didn't put the wheels in for you, in most locations the holes for the mounts are pre-drilled.

Photo 6
Photo 6
The parts required are the same as listed above.

For the SC10-2 you can add up to four additional wheels at the front of the skid, and two wheels at the rear, just ahead of the rear axle.

Doing the rear wheels is easiest since there is no disassembly required. Use a 5/16" (or 8mm) drill bit and drill out the existing 6mm holes (see photo 6). This shows the existing holes in the stock rails.

After drilling out the holes, simply install the previously listed parts that make up the wheel kit (see photo 7).

Photo 7
Photo 7

Moving toward the front of the sled, remove the front inner wheels then remove the support from the rail. Move the support forward on the rail until it is centered between the two "windows" in the slide rail (see photo 8). Use a center punch and the support as a guide to mark holes to be drilled for the support. Drill two new mounting holes using a 5/16 (or 8mm) drill bit. Reinstall the inner wheels in this new location. (Remember, on the inner wheels PN 503173700 washer is not used in the assembly.)

You can now install a new wheel/support assembly on the OUTSIDE of the rail in the location where the inner one was originally located.

Photo 8 Photo 9
Photo 8 Photo 9
(A word of caution here, if you're banging your sled hard all the time to where the rear suspension bottoms fully, the arm of the torsion spring MAY come in contact with the wheel support. If you are concerned that this condition may occur on your machine, you can leave the outside support and wheel off. To check for clearance, remove the wheel (leave the support on the rail), load the sled with all your friends to squash the suspension down to the bump stops. Visually check to see if the torsion spring arm contacts the wheel support.)
Photo 10 Photo 11
Photo 10 Photo 11

Re-install the OEM outer wheel that is forward of the coil spring support bushing. Photo 9 shows the inner wheel in the new location and the new outer wheel. Remove the front most outer wheels. Use a 5/16" (or 8mm) drill bit and drill out the existing 6mm holes (see photo 10). This shows the existing holes in the stock rails. After drilling out the holes, simply install the previously listed parts that make up the wheel kit (see photo 11). Then re-install the outer wheel. Photo 12 shows all the wheels installed at the front of the skid.

Photo 12 Photo 13
Photo 12 Photo 13

Photo 13 shows what it looks like when it's all back together. With this setup, hyfax wear is reduced as well as the drag and friction that scrub off HP. When you encounter marginal snow conditions, your machine will be able to survive without melting the hyfax to the track.

 


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