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Discussion Starter · #1 ·
Does anyone know anything about using a 141" track on 136" rails (I've got a 2000 RMK 700) by simply moving the rear suspension mounting back 2-3 inches? I saw mention of it somewhere and am curious as hell if this can be done without extensions. Anyone got any word on this??? Thanks!
 

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There's no way you'll be able to make up the 5 extra inches of track without buying rail extensions. You could make up 3 inches (say going from 133 to 136) by getting the 8 inch rear idler wheel setup....but in your case you've got to get the rail extensions.
 

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RMK2play, You have to remount the rear skid. This will not only allow you to use a longer track it will improve your angle of attack so that you get up on the snow better. It can and has been done a number of times. It was the solution to Yamahas probems in 99 track angle was to steep so they went from a 136 to a 141 and all they did was move the entire rear skid back. I am going to use 144 rails and a 151" track and due this same thing on my T-cat. Some local shops in your area should be able to help you out with your specific application. The 2001 rails I am going to use utilize a different size rear wheel so I am going to have to adjust the amount that I move the rear skid back but this shouldn't be a problem. You may need to add additional reinforcement to your tunnel where you redrill the hole to mount the front of the skid if your stock plates don't come back far enough. You will also have to move the rear mounting hardware the same distance if you want to keep your suspension geometry the same. Good luck, It will cause you to have a little rougher ride on the trails but if you are like me riding the trails isn't why you are considering doing the project in the first place.
 

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Discussion Starter · #4 ·
Thanks 2000TCMC for the word. So it sounds like i just have to move the four mount bolts back an equal distance to keep the suspension geometry and I was thinking I can probably make up at least an inch of track with the rear wheel adjustments (so i might get away with only moving things 3" or so?). However, I was considering going to a BIG back wheel set up (maybe 8") but won't that rob me of an inch or so that i'm trying to gain??
 

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It will take away a small amount from the contact patch but what you will gain back in HP is worth it. There are a couple of sites on the web that explain the process in better detail, been there just don't have the URL handy. I think people have been moving the rear skid back like 2" with the big wheel kit. if it is a new track be careful trying to make up for it with the rear adjusters you don't want to run out of adjustment when your track stretchs.
 

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Discussion Starter · #6 ·
Thanks again 2000TCMC. Good point(s). I'm gonna do a little investigating to find the correct measurements. It looks like the four reinforcement plates for the rear susp. mounts would all have to be relocated (about 10 rivets each) or possibly (if i went to a 144" track) just adding a second set in the new position (say 5" back).
Anyway much appreciated and I'll keep posting my findings for anyone else out there that has a 136 "long" track they're thinkin about stretching for ridin'/climbin' in DEEP POW.
p.s. i just found this site and.....This site kicks ass.
 

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I will post pics of my project after I am done this summer stretching it out to 151 from 136 Have all the parts except track and tunnel extension (hope to pick those up in the next month or so)
Welcome aboard. And your right this site is great (No bashing bull S%$#) just people who love the sport.
 

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Discussion Starter · #8 ·
Right on! I'll keep checkin for those pics. I was wondering about how long you can stretch a 136 without having to get a new tunnel.

Cause it looks like I only have enough room on my tunnel to move my rear skid supports about 6" back....but I guess with 144 rails i'd only NEED to move things 6" or so to also get to 151. Your plans have got ME thinking. With this setup how long is your tunnel extension going to be? 15" ? any down side to doing this beside a little rougher ride on the trails? how about through rough bumps and overall handling? just wondered if you might know first hand or from any of yo friends that have done this type of mod.

p.s. Still snowing in TAHOE just got another 1 1/2' @ 8000' the other night.....we've got as much snow as we did in freakin February over 8000'. What spring? I think we're going straight to summer next month.
 

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I am going to add the 136 to 151 factory tunnel extension. It moves the rear cooler back where it will get more snow on it for cooling. I don't know the dimensions of the extension but my guess would be 7 1/2" or so. I am going to add additional tunnel plates to mine can't hurt to add a few extra ounces to the sled for strengths sake.

With the 144 rails I am only going to move the rear skid back like 3 to 3 1/2" because of the largers diameter rear wheels required for the rails I'v got. I wouldn't suggest moving it back further or you will really start messing with your suspension geometry and weight distribution.
 
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Highsierra,
Yes, you can put a 141" on a 136" without extension. We have done it. Remember, the 5" gain in track length only relates to 2.5" of adjustment to the rear idlers. We did it by grinding out the back side of the round holes to fit the square mounts on the polaris axle. We only took a small amount of material out of the rails and it went in just fine. We did this on a Crazy Mountain Extreem, which is basically a Polaris.

Dennis
 
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/polarisman/../images/users/D Noel/full sled.jpg
RMK,
This was a 136x 1.25 sled converted to a 144 x 2". I used rail extensions and 8 tooth drivers. everything else stock, including tunnel and suspension.
 
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