Rail extension theory... Am I way off?

[sorenson464]

I posted this in the ski doo forum first... I think this may be a better place for it. I have an 01 mxzx 440 and i was thinking about putting a 128" track on it, I would prefer a 133, 136 is long for a 440 in my opinion, but i was looking at rail extensions and if my figuring is correct 133 isn't an option but i could be way off.

So in my head this makes sense...

Tracks:
133-121=12
128-121=7

Rail Ext:
151-144=7
136-121=15

So if I used the 151 to 144 it would give me the seven inches, could i use the 136 with a big wheel kit?

This is total guess theory, who knows i could be correct. Any ideas?
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[farmboy84]

well your extension will be approximately half as long as the additional track length. if you went from 121" to 136" that is 15" of track so you need around a 7.5" extension.

your asking if a 144 to 151 extension would work for you to go to 136", no it wouldn't. the extension would only be 3.5" long.

 

[sorenson464]

well your extension will be approximately half as long as the additional track length. if you went from 121" to 136" that is 15" of track so you need around a 7.5" extension.

your asking if a 144 to 151 extension would work for you to go to 136", no it wouldn't. the extension would only be 3.5" long.

my bad i meant to say could i run a 133 with the 144 to 151 extension and a big wheel kit?

 

[05snopro440]

I'm pretty sure you'd still be about a half inch short.

 

[banditpowdercoat]

Go for a 136" track on that 440. I have a 136 x 1.5 on my wifes 440F Poo. and that thing goes darn near anywhere. No matter what, not enough power to really trench, so it just chuggs along. Follow in someones track and she'll get there. and its fun to boondock with. A REAL challenge when your power limeted

 

[sorenson464]

Go for a 136" track on that 440. I have a 136 x 1.5 on my wifes 440F Poo. and that thing goes darn near anywhere. No matter what, not enough power to really trench, so it just chuggs along. Follow in someones track and she'll get there. and its fun to boondock with. A REAL challenge when your power limeted

I had a 440f Polaris with a 133x1.5 and that was allot of track for it, and yeah I never got stuck and it was a ton of fun but I just dont think i wanna cut my power by putting a big track on the 440, thats why i was hopping to stay to a 128 or 133... Idk a 133 or 128 1.5 seems better to me than a 121x2... Just not sure what to do

 

[banditpowdercoat]

I had a 440f Polaris with a 133x1.5 and that was allot of track for it, and yeah I never got stuck and it was a ton of fun but I just dont think i wanna cut my power by putting a big track on the 440, thats why i was hopping to stay to a 128 or 133... Idk a 133 or 128 1.5 seems better to me than a 121x2... Just not sure what to do

That old 440 just pulled my 151 Doo outa the bush, I lunched a crank It's pulled 3 yami's, 2 cats and 2 my doo twice...

You realize 133-136 is 1.5" track I bet not noticable

 

[viperxc]

Just wondering if the weight between a 133" track and a 136" track is even enough to worry about. I didn't even see a 133" track listed on a vendor site when looking for weight difference.

If unsure about the 136" track then I would suggest to go with the 128". I would stay with more common sizes for future buying/selling of parts.

 

[sorenson464]

Just wondering if the weight between a 133" track and a 136" track is even enough to worry about. I didn't even see a 133" track listed on a vendor site when looking for weight difference.

If unsure about the 136" track then I would suggest to go with the 128". I would stay with more common sizes for future buying/selling of parts.

133 was stock on the late mid to late 90's rmks and touring sleds

 

[poorider]

running a 136 on your 440 is no more too big of a track than some of these guys who put 174's on their stock 700's. I highly doubt you would notice any diffence between a 133 and a 136, in fact with the newer designed lighter 136's out nowadays you would probably be better off with a 136 over the old polaris 133 tracks.

 

[roughrider99]

honestly a 440 will pull a 133 all day long, honestly your sled will be fine with a 136 its only 3 inches of extra track, it will not make one bit of difference at all. For simplicity go 136 your 440 will rip all day long with that track, go ride.

 

[banditpowdercoat]

Like I said previous, My wifes 440Fan Indy turns the 136 x 1.25" track nicely, It's acctually impressive where that lil sled will go. Can't climb with the 800's but it finds its own way up the hills. Can sidehill forever LOL

 

[wrtmani]

track question

Go to tracksusa.com all they deal in is snowmobile tracks and related parts (rail extensions, tunnel extensions, skids, sprockets, etc). They are a small outfit with a large following.

Another source I use quite a bit is the online snowmobile catalog for Western Power Sports (wps-inc.com). Their online snowmobile catalog lists rail extensions from Van Amberg, MMP, and their own WPS line. The WPS line has a real good chart listing axle extension required for various track lengths (as stated before, it is 1/2 the track legnth change for axle extension legnth.) Also, keep in mind track lug height and drive pitch. Different pitches use different diameters of sprocket. and you may have to change to a lower/higher tooth count to gain the same clearance for a given lug height (WPS's catalog also has some really good charts for this also).

You will not find a new 133.5 track anywhere (I'm pretty sure even the Polaris dealers don't have them anymore). Dennis Kirk's catalog says that for all 133.5" Polaris machines to order a 136" track and set the skid back 1 1/2 inches. I am putting a 141" x 2" on my XLT this fall. I can use either 136-144 extensions on my 133 rails, but I bought a set of 136 rails to fit my skid that I will use 136-141 / 151-156 WPS extensions so that if I decide to go with a 151 track down the road I will be able to get them easily (136-151 extensions are the same 7.5" axle extensions to take a 121-136 which is very popular to do).

Hope this long-winded answer helps!

 

[Reeb]

Not really a fair comparison, but it's what I have.

121x2 Bighorn with a stock 121 Sno-X skid('01 Snopro)
141x2.25 Camo Extreme with '09 rails and '06 running gear.

Came out to the exact same weight. This was before I drilled the track.

Was put on a A/C 440F and carried the skis 550ft all the way to two 1st place finishes at our local drag races a few weeks ago. Junior 600 Liquid and Stock 500 class.