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Discussion Starter · #1 ·
Stretching my 2007 440x race sled to the 137" BCX2 track.

I finally have it all in there and the track is sagging way too much (very loose).

Has anybody gone from the 120" to 137" rail extension and had a similar problem?

What was the solution going to 8" wheels with offset axles?

Frustrated at this point as they are telling me i'm the first to have this problem and they've sold hundreds of these kits.
 

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Post some pics, tracks usa has a pretty solid rep but mistakes are possible. I was looking at this exact setup but decided on 146.
 

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Did the kit on a 121 to a 136 this past fall. No issues for us at all.
 

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I was going to post on update on this as I just did the exact setup with my 2004 440x to a 137 with Tracks USA extensions and a track from a BCX. I had already converted my drivers to 8 tooth 2.86.

With the stock adjuster bolts you cannot get the slack out of the track because the 137's use the bigger real wheels.

What I did was take the collars off the stock adjuster bolts which prevent you from getting the full adjustment from the bolts. I am fully aware these collars are there to add strength but 1000 miles later of hard riding zero issues. Once the axle is tightened down the load is carried through the rails, not the adjuster bolts. With the collars off you can get an extra 1/2-1 inch of adjustment which will allow you to use the stock setup. With the my track tensioned properly I still have an inch or more at the back of the slotted hole in the extensions.

Please use blue loctite on your axle bolts if you do it this way and ensure they are torque properly with OEM or a good hardened bolt.

I used my stock 440x axle and moved 3 wheels to the inside. My axle was worn on the outside where the bearing races had started to spin which was my only reason for doing it. I will post some pics tommorow.

An offset axle is the more expensive choice, but absolutely not necessary.
 

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I was going to post on update on this as I just did the exact setup with my 2004 440x to a 137 with Tracks USA extensions and a track from a BCX. I had already converted my drivers to 8 tooth 2.86.

With the stock adjuster bolts you cannot get the slack out of the track because the 137's use the bigger real wheels.

What I did was take the collars off the stock adjuster bolts which prevent you from getting the full adjustment from the bolts. I am fully aware these collars are there to add strength but 1000 miles later of hard riding zero issues. Once the axle is tightened down the load is carried through the rails, not the adjuster bolts. With the collars off you can get an extra 1/2-1 inch of adjustment which will allow you to use the stock setup. With the my track tensioned properly I still have an inch or more at the back of the slotted hole in the extensions.

Please use blue loctite on your axle bolts if you do it this way and ensure they are torque properly with OEM or a good hardened bolt.

I used my stock 440x axle and moved 3 wheels to the inside. My axle was worn on the outside where the bearing races had started to spin which was my only reason for doing it. I will post some pics tommorow.

An offset axle is the more expensive choice, but absolutely not necessary.
I would like to see pics of your 3 wheels inside. Was going to do two wheels myself for better carving but 3 inside sounds better. Also how do you like the track and for what kind of riding?
 

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People are often confused with the 3rd wheel but if your doing 2 why would you not add the 3rd?? All stock parts used, only had to trim the 2 inside collars for the center wheel.

My riding style is everything from ice fishing, to hill climbing, trail riding, water-x, but for hardcore trail riding, this 440x chassis with no sway bars is noticeably tipper at slow speeds without the outside wheels, but for everything else it's a nice improvement but nothing drastic. I'm running wide C&A Ultras so anything I can do to get it to layover helps.

I only did this because my axle was chewed up on the outside. Now that I have ridden with it like this I would not change back.

I will post pics tommorow, also fabbed a custom tunnel extension.

Tracks USA markets their extension as a 136.
 

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Forgot to add, I hate this thing on the trails with the 137. I rode this sled for 4 years as a 121. With the ported/piped/ RK-Tek head, Dj clutched etc it was a blast to ride on twisty trails. In fairness I haven't touched my suspension which was dialed in with the 121. I was prepared to give up the trail handling for the off-trail performance so I have no regrets.
 

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People are often confused with the 3rd wheel but if your doing 2 why would you not add the 3rd?? All stock parts used, only had to trim the 2 inside collars for the center wheel.

My riding style is everything from ice fishing, to hill climbing, trail riding, water-x, but for hardcore trail riding, this 440x chassis with no sway bars is noticeably tipper at slow speeds without the outside wheels, but for everything else it's a nice improvement but nothing drastic. I'm running wide C&A Ultras so anything I can do to get it to layover helps.

I only did this because my axle was chewed up on the outside. Now that I have ridden with it like this I would not change back.

I will post pics tommorow, also fabbed a custom tunnel extension.

Tracks USA markets their extension as a 136.
Sweet looking forward to the pics
 

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Sorry forgot about this!! On the outer axle bolt I used a piece of 1/4 alluminum channel re-shaped to add extra strength where it is acting as a washer against the adjustment slot. Sorry bout the pics, I'm not good at that stuff. Also fabbed a custom tunnel extension because the aftermarket ones just look plain. This one will let me dig down deeper, sometimes it's the difference between getting stuck or powering out.

left-wheels.jpg left-tunnel (3).jpg
 

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If you look at the adjuster bolts on the inside you will see the collar missing. You could actually take a 1/3 off, maybe a half and it could still be used. Again, like I said I have zero issues and in a low snow year I have hit a tonne of rocks.
 

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If you look at the adjuster bolts on the inside you will see the collar missing. You could actually take a 1/3 off, maybe a half and it could still be used. Again, like I said I have zero issues and in a low snow year I have hit a tonne of rocks.
Awesome looking sled, love the tip up running boards and extension. So just to be clear you just used stock spacers to install the 3 wheels and made the keepers for outside the rails? What year skid is that, don't remember mine having the forward coupling stop?? Or maybe it does can't remember.

Thanks for the PICS
 

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This is an SC10-3 rear skid. I took the factory outer spacers or collars with the groove cut for the adjuster bolts, those went right inside the rails. The length is perfect to center the wheels inside the track nubs. Then the for the inside wheel t was just some careful measuring and cutting making sure the inner wheel is well supported with the spacers, you cannot have a gap but remember when you tighten the outer bolts it will compress everything to together.

The outer alluminum piece I made will do a better job of holding tension then a fender washer or anything similar that may try and puil into the adjuster slot. A 1/4 piece of alluminum cut into a circle would also work just as well.

You also have to cut one end of the axle and drill tap. I cut and tapped both because of the wear on the shaft from bearings spinning. I converted them to 3/8 instead of metric.
 

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Discussion Starter · #14 ·
I was going to post on update on this as I just did the exact setup with my 2004 440x to a 137 with Tracks USA extensions and a track from a BCX. I had already converted my drivers to 8 tooth 2.86.

With the stock adjuster bolts you cannot get the slack out of the track because the 137's use the bigger real wheels.

What I did was take the collars off the stock adjuster bolts which prevent you from getting the full adjustment from the bolts. I am fully aware these collars are there to add strength but 1000 miles later of hard riding zero issues. Once the axle is tightened down the load is carried through the rails, not the adjuster bolts. With the collars off you can get an extra 1/2-1 inch of adjustment which will allow you to use the stock setup. With the my track tensioned properly I still have an inch or more at the back of the slotted hole in the extensions.

Please use blue loctite on your axle bolts if you do it this way and ensure they are torque properly with OEM or a good hardened bolt.

I used my stock 440x axle and moved 3 wheels to the inside. My axle was worn on the outside where the bearing races had started to spin which was my only reason for doing it. I will post some pics tommorow.

An offset axle is the more expensive choice, but absolutely not necessary.
I ended up removing the stock collars and it gave me enough to get the track tightened up to about 1.5"-2" of slack. Hopefully the track does not stretch. I was told that track's don't stretch, they just become more pliable. Is this the truth? I always assumed they would just stretch a bit after use.

Either way got it together and on the snow.. the rear bumper/grab bar was a real struggle and didnt fit properly so I had to re-drill some mounting holes and man handle it into place.
 

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I haven't adjusted mine in 1000 miles. Just make sure you keep a close eye on the rear axle bolts, check the torque every few hundred miles.
 
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