Shimming skis

[Doug]

To help reduce darting and even out carbide wear many guys have been shimming the skis.  Ski alignment also has a lot to do with darting so make sure your ski alignment is good and make sure the skis are not toed in at all.  Shimming also helps with carbide wear.  Without having the skis shimmed you'll find that the front of the carbide will wear a lot faster than the rest of the carbide.  By shimming the skis this evens out the wear.  Attached is a print of what the shim looks like and can be made from a 1/4 plastic.  Some guys have used a section of slide cut 1/4 think.  The shim is install between the ski rubber (item 7) and lays in a pocket in the ski.  When reassembling you will have to use a little force on the ski to help align the mounting bolt.

[Zambroski]

Nice technical post, Douglass!

Shimming is a matter of personal preference.  It does effect handling to a degree and it depends on how you ride.  But the ones that do it, swear by it.  I think Poo machines benefit greatly with shimming based on the amount of people that have sworn by it over the years.  If your carbides are wearing weirdly, it may be necessary.

[Bontz]

11 hours ago, Zambroski said:

Nice technical post, Douglass!

Shimming is a matter of personal preference.  It does effect handling to a degree and it depends on how you ride.  But the ones that do it, swear by it.  I think Poo machines benefit greatly with shimming based on the amount of people that have sworn by it over the years.  If your carbides are wearing weirdly, it may be necessary.

This is what I would see ... the front of the carbide & host bar would wear unevenly.  Easy fix.

[Crnr2Crnr]

On 12/22/2020 at 7:59 PM, Zambroski said:

Nice technical post, Douglass!

Shimming is a matter of personal preference.  It does effect handling to a degree and it depends on how you ride.  But the ones that do it, swear by it.  I think Poo machines benefit greatly with shimming based on the amount of people that have sworn by it over the years.  If your carbides are wearing weirdly, it may be necessary.

It's not just Polaris, the C&A and Curve ski rubbers under the spindles are different when sat side by side with Cat stockers and I've seen more consistent wear with 8" carbides after switching to C&A's.  First time mounting the C&A's on a fresh set of dampers under the spindle takes a little patience.  Found the 2x4 trick works well, then mount the carbides.

[irv]

16 hours ago, Crnr2Crnr said:

It's not just Polaris, the C&A and Curve ski rubbers under the spindles are different when sat side by side with Cat stockers and I've seen more consistent wear with 8" carbides after switching to C&A's.  First time mounting the C&A's on a fresh set of dampers under the spindle takes a little patience.  Found the 2x4 trick works well, then mount the carbides.

I tried and tried to shim my Curve skis but had no luck. The rubber/ski assembly was way to tight to even think about getting shims under there. When I first purchased them and was installing them, I needed the 2x4 and a lot of muscle and pounding just to get them installed. When I read about the shim trick I knew right away it likely wouldn't work but I tried anyway to no avail. I believe when I received my Bergstrom Triple Points, 3 different sets of shims came with them.

[Doug]

Guys that are cutting a piece of Hyfax and using it as a shim check them to see if they are collapsing.  Worked on a couple sleds now and seen wear the front of the carbides were wearing and figured that skis were not shimmed.  Pulled the skis off and found where they had used a piece hyfax and it was collapsed and basically not doing anything to shim the ski.

[Doug]

[jonlafon1]

Good post!  The key is to really pay attention to carbide wear from front to back and adjust shim thickness.  Did this for years on Cats.. Recently I switched to sno trackers with ZERO tow on alignment and no shimming  OR.. Actually with cat skis I shim them with a VERY thin shim in the FRONT not back.. Different carbide and set up but I NEVER thought that trackers were something I would use but boy when I did they were awesome.. My buddy behind me even commented He could not hold the speed through the turns after I started using trackers..  And we BOTH always ran slim jims with shimmed skis(cat skis). I found the 6" were actually better then the 8" slim jims..  Its all relevant to your set up on your sled.. Getting the balance correct and making adjustments very slight with spring pressure on the fronts and middle.. 

[Doug]

Just to see the comparison the ski on the right is shimmed on the left not shimmed.

[Bontz]

I didn't take a picture, but my VR1 is sitting in my garage on the EZ-Mover and you can clearly see the skis are damn near pointed down at the ski tips.  It's crazy to think Polaris couldn't come up with a better ski rubber, or even a change to the ski design so the existing rubber would force the shimming effect.

[Deephaven]

Even with good rubbers time makes that happen.  I get new rubbers for my powder pro every few years and in between shim them.

[Doug]

6 minutes ago, Bontz said:

I didn't take a picture, but my VR1 is sitting in my garage on the EZ-Mover and you can clearly see the skis are damn near pointed down at the ski tips.  It's crazy to think Polaris couldn't come up with a better ski rubber, or even a change to the ski design so the existing rubber would force the shimming effect.

The simplest would be to make a change to the rubber support.  

The sled I was working on had the front of the carbides worn almost to the bar and the back still 3/4 good.

[Mag6240]

Since I went with the Stud Boy 9” deuce I haven’t seen that front carbide wear issue, no shims here.

[Doug]

4 hours ago, Mag6240 said:

Since I went with the Stud Boy 9” deuce I haven’t seen that front carbide wear issue, no shims here.

Good to know.  With the duel carbide and further forward on the bar may be the trick.

Here's what I typically see with carbide wear on unshimmed skis with a standard single carbide runner

[Mag6240]

Yeah I haven’t seen bars worn like that since my 2008 IQ - I’ve run these since day 1 on all my Axys sleds, and this is just the front of the bar, (I was going to post it in your other Woody’s protector thread) but you can see, the carbide is only worn on the very front of the two rows of carbide.  This one has 11k miles on it.