DURA PRO Ski Dampener in ARO/RIOT SKI

CATSLEDMAN1

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Nov 27, 2007
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Last weekend Dan and I decided that 2 years of riding , the ski dampener in our ski were fatigued out. Ski too floppy, specifically, when turning or sidehilling the loose dampener was allowing the ski tip to rise up tooo much, which is way bad on a snow bike.

Hawkster had mentioned the DuraPro dampener might be a good stepup in performance. Found the DuraPro website, looked like only one model of dampener available for Polaris ski, $79.00 a pair +shipping, ITEM # 1018901. By Friday they were on the bench. Pulling Riot ski off and comparing stock with the DuraPro we were not sure this setup was going to work. Profiles different by quite a bit. Way stiffer material than stock, which is what we were after, so should we blow $80 and try to make them work, went for it.

1. DuraPro was made for entirely different ski base. Nubbins on the back of DuraPro had to be cut off in the band saw, ok return option done.
2. the new much wider DuraPro fits, no problem width wise, so a much wider support was going to be a plus.
3. DuraPro would be too thick if you place it on top of the raised boss cast into the ski. Never ever get a bold in. The RIOT ski has an oblong plastic boss the stock dampener sits in. We could see that has to go, and inside that oblong boss was only a grid / not a flat supportive surface for the dampener to sit on, that had to go.
4. We have all fought with trying to cram a ski dampener in place and get the bolt through and it was obvious this was never going to happen, we unbolted the aluminum ski holding block so when it was time to put all together, we put it in a press.
5. We cut a 1/4 thick piece of aluminum to fit inside the boss, then took a sharp wood chisel and planed the boss plastic flat to the aluminum.
Putting that together in the press was too much pressure on the ski and the bolt , might bend a bolt might explode the ski. Back apart and cut the next thinner aluminum to go in l the boss and replaned the boss plastic down to this thinner aluminum. Almost good, but still to tight. Next aluminum thickness seemed about right, replaned boss and pressed it all together. So we settled on 1/8" thick base with the plastic trimmed to fit.
Trimming the ski plastic boss would not preclude you from putting the stock dampener back in and running it stock. If you trimmed the boss away entirely, you should be able to put the DURPRO in and the ski bolt through as per stock set up. since we already had shims under the stock rubber, the 1/8 aluminum gave us a nice tight fit. One day of riding, its loosened up for sure.

6. Back on the bike, dropping the bike down, now the ski has a forsure ski up attitude. Hmmmmm, not sure how thats going to work, what it does do is on hard surfaces like icy roads and old sled tracks, you ride on the back half of the center carbide when your ski contacts any bump/rut/, and that could be good.

7. Next morning a good test. Bluebird day with hard packed road for 1 mile, old sled tracks and bike tracks from the sunny day before. Right away its a noticeable improvement . We crossed back and forth on the sled ski ruts, ran down sled ski ruts, that ski up attitude and always defaulting to the back half of the carbide making contact as you cross ruts, way good.

8. Will the already ski up attitude be a screw up as we climbed into dense powder, nope. We cut some near vertical road bank side hills with 6" of dense fluff on old base, great. More precision in turning tight in the trees......that was good. End of a 6 hour ride, for now we think a positive all the way around. Lets you carve a turn with no surprises, carve a turn across old ruts without being as grabby. At least we though so.

9 Would replacing the the shot stock dampener with a new one been just as good ? We might try that now. For my Riot, I don't think so. The last half mile going to the truck, really hard packed sled trail /cross county ski trail, ATV tracks, and starting to get soft in places, best my bike has ever handled a junk trail WFO in 6th, Dan on his ARO..........well not so sure.
 

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Sheetmetalfab

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Last weekend Dan and I decided that 2 years of riding , the ski dampener in our ski were fatigued out. Ski too floppy, specifically, when turning or sidehilling the loose dampener was allowing the ski tip to rise up tooo much, which is way bad on a snow bike.

Hawkster had mentioned the DuraPro dampener might be a good stepup in performance. Found the DuraPro website, looked like only one model of dampener available for Polaris ski, $79.00 a pair +shipping, ITEM # 1018901. By Friday they were on the bench. Pulling Riot ski off and comparing stock with the DuraPro we were not sure this setup was going to work. Profiles different by quite a bit. Way stiffer material than stock, which is what we were after, so should we blow $80 and try to make them work, went for it.

1. DuraPro was made for entirely different ski base. Nubbins on the back of DuraPro had to be cut off in the band saw, ok return option done.
2. the new much wider DuraPro fits, no problem width wise, so a much wider support was going to be a plus.
3. DuraPro would be too thick if you place it on top of the raised boss cast into the ski. Never ever get a bold in. The RIOT ski has an oblong plastic boss the stock dampener sits in. We could see that has to go, and inside that oblong boss was only a grid / not a flat supportive surface for the dampener to sit on, that had to go.
4. We have all fought with trying to cram a ski dampener in place and get the bolt through and it was obvious this was never going to happen, we unbolted the aluminum ski holding block so when it was time to put all together, we put it in a press.
5. We cut a 1/4 thick piece of aluminum to fit inside the boss, then took a sharp wood chisel and planed the boss plastic flat to the aluminum.
Putting that together in the press was too much pressure on the ski and the bolt , might bend a bolt might explode the ski. Back apart and cut the next thinner aluminum to go in l the boss and replaned the boss plastic down to this thinner aluminum. Almost good, but still to tight. Next aluminum thickness seemed about right, replaned boss and pressed it all together. So we settled on 1/8" thick base with the plastic trimmed to fit.
Trimming the ski plastic boss would not preclude you from putting the stock dampener back in and running it stock. If you trimmed the boss away entirely, you should be able to put the DURPRO in and the ski bolt through as per stock set up. since we already had shims under the stock rubber, the 1/8 aluminum gave us a nice tight fit. One day of riding, its loosened up for sure.

6. Back on the bike, dropping the bike down, now the ski has a forsure ski up attitude. Hmmmmm, not sure how thats going to work, what it does do is on hard surfaces like icy roads and old sled tracks, you ride on the back half of the center carbide when your ski contacts any bump/rut/, and that could be good.

7. Next morning a good test. Bluebird day with hard packed road for 1 mile, old sled tracks and bike tracks from the sunny day before. Right away its a noticeable improvement . We crossed back and forth on the sled ski ruts, ran down sled ski ruts, that ski up attitude and always defaulting to the back half of the carbide making contact as you cross ruts, way good.

8. Will the already ski up attitude be a screw up as we climbed into dense powder, nope. We cut some near vertical road bank side hills with 6" of dense fluff on old base, great. More precision in turning tight in the trees......that was good. End of a 6 hour ride, for now we think a positive all the way around. Lets you carve a turn with no surprises, carve a turn across old ruts without being as grabby. At least we though so.

9 Would replacing the the shot stock dampener with a new one been just as good ? We might try that now. For my Riot, I don't think so. The last half mile going to the truck, really hard packed sled trail /cross county ski trail, ATV tracks, and starting to get soft in places, best my bike has ever handled a junk trail WFO in 6th, Dan on his ARO..........well not so sure.

I’m just surprised you didn’t try this sooner.

The aro rubber was floppy out of the box on my sxf450. (Christmas 2018)

I had a polyurethane tight ski rubber the second ride.

It’s such a great improvement.
 

CATSLEDMAN1

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what polyurethane ski rubber did you use ? I have looked for other alternatives and shimmed all my ski rubbers to make then tighter, carved a hockey puck to make a tighter ski on the early TS ski.
 

Sheetmetalfab

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what polyurethane ski rubber did you use ? I have looked for other alternatives and shimmed all my ski rubbers to make then tighter, carved a hockey puck to make a tighter ski on the early TS ski.

I used some ski rubbers from Sweden before the durapro was available (made by member “Gulfi” here on snowest)

Then switched to durapro when they became available.

Shimming is good too but the timbersled rubber was/is soft.
 

Sheetmetalfab

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Why do they even use rubber?

I assume polaris does because it’s cheap.

The durapro is polyurethane “rubber” similar to aftermarket 4x4 truck suspension bushings.

Self lubricating.
 
Last edited:

Sheetmetalfab

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What I mean is the rubber seems to cause more problems than it solves and a ski that can’t pivot much at all would almost seem like a better solution?

I think the issue ends up being that a solid mounted ski would be damaged when forced to move from a hard hit.
 
Feb 8, 2010
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The ski has to be flexible enough to allow it to pivot when turning and cranking nuts and stiff enough so the ski doesn't become a plow. With the ski being flexible one can initiate a turn etc. quicker and sharper, too soft will turn the ski into a plow.
 

Hawkster

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Two reason why plastic skis replaced metal , lack of friction and flexibility . Plastic skis of just recently have become very rigid and light .
SLP use to make a plastic and chrome moly frame , might still be one of the lightest ski even today , they did crack but it was also an easy fix usually behind the welds .
Sleds have found out rigidity in pivoting is a good thing also .
Now put a ski that pivots a little to easy on forks that where never designed to have such a broad foot print . A ski that pivots a little to easy is kind of like running those forks into an unsuspected log under the snow . That is a crap load of force being applied from that pivoting ski to those forks designed for a tire . Amazing the beating they take but that flexing could of been part of the reason people break spindles also .

Some of the sledders are also breaking the ski loops when ridden hard on these newer skis , the solution is to loosen up the ski loop bolt a little to allow a little flex .
 

Hawkster

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For as light as the snow bikes are they should see the benefit of this when a much heavier machine can pull this off . I quite counting at around 20,000 and it's has to be a good 30 at least now . Only thing I ever broke was those stupid bolts until I started making my own and than you guys ended up with the same stupid sh!t . Until they started making the correct bolt . Fly over the bar just once and that crap won't happen again :)
This is how rigid I run my skis , the ski rides the heel .
Second picture shows you how much rubber there actually is , I made the saddle before yeti actually made one for Hawks , bolt is twice the size of snow bikes .
IMG_20210320_181906926_HDR.jpg IMG_20210320_164550378_HDR.jpg
 
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