E-Bay Spitfire with rubber conversion track

ChickenRat · Post by **ChickenRat** » Wed Jan 16, 2008 3:49 pm

http://cgi.ebay.com/ebaymotors/1979-John-D...tem200192548192

Spitfireguy · Post by **Spitfireguy** » Wed Jan 16, 2008 5:36 pm

wow that be sweet with about 96 studs. man that spit would go!

mwking · Post by **mwking** » Fri Jan 18, 2008 10:28 pm

If anyone on this board buys that Spitfire or even gets a good look at it it would be interesting to get the details of the rubber track conversion. It would be great for the owners of the direct drive sleds to know that there is a way to get a new track when the time comes for one. A thread with pictures detailing a conversion would also be interesting if anyone has completed one. I would hate to think that people are not buying or fixing up a lot of Spitfires, Snowfires, Sprintfires or even Trailfires and early Sportfires because they figure you can't get a track. Getting a Liquifire suspension for a Trailfire or early Sportfire may seem too difficult or expensive to some people, but at least there is a clear path to follow to get your sled going again.

JDT · Post by **JDT** » Sat Jan 19, 2008 4:18 am

I have done several track conversions but not on Deere's. Mostly Scorpions that ran the Rubber Drives INC tracks. These were affectionately known as the "barn cleaner" tracks.
I have also done Viking track updates.

The basic upgrade would be track and drivers.

There are Deere conversion kits out there similar to what Central sells but they require moving the suspension forward like 2". To do this correctly demands that you move the tunnel reinforcement plates forward also. If you don't, the bolts will blow out a hole in the aluminum and you have a major problem.
Besides that it looks corny with the track being shorter.

I am unaware of any other sled ever made that used the same track as the Spitfire.

But I bet there is something close. What are the specs on a OEM Spitfire track? Maybe I can figure out a fix.

Todd

400brian · Post by **400brian** » Sat Jan 19, 2008 5:01 am

Todd

Have you looked at the Track Interchange FAQ?

Liquifire 4/6 · Post by **Liquifire 4/6** » Sat Jan 19, 2008 9:43 am

I bought a parts Spitfire about a year ago and someone had installed an all rubber Ski Doo track on it (looked like a track from a mid seventies Olympique). It's in a snowbank in my backyard right now and I'd have to dig for 2 hours to get any pics of it. It was not what I'd call a successful conversion. The guy used Ski Doo external drive sprockets of a considerably larger diameter than the Spitfire sprockets which made for way too tall gearing. This resulted in the drive clutch sheaves wearing out completely ( the inner sheave of the 94C was actually completely seperated from the shaft). The driven clutch was also a mess with the torque buttons totally melted and the helix destroyed. The belt that was on it had worn down to about 1/2" in width. I'm guessing that is exactly what this guy did and it probably will work about as good....unless he was able to locate smaller Doo Doo drive sprockets (it sure does look like a Bombardier track in the pic). So while it works to some degree, it isn't much of a solution as far as I can see.

mwking · Post by **mwking** » Sat Jan 19, 2008 2:32 pm

Well Liquifire 4/6 I guess the problem isn't just finding a conversion and documenting it but finding one that actually worked acceptably. Todd, I have heard of the conversion kits that Central sells but I haven't seen a machine that has one installed or even heard what the kit contains. I've heard on this site and elsewhere of converting to a Yamaha, direct drive Polaris, or Arctic Cat Jag track as being possible solutions but have never seen anything where someone completed the conversion and was happy with it. I was just thinking that if we could document the conversion process with pictures it would go along way to convincing some people that these sleds have a future. Todd, according to the faq the Approx. dimensions are: 116" X 15 with a 2" drive lug pitch

That Girl Racing · Post by **That Girl Racing** » Sat Jan 19, 2008 2:43 pm

It is done with Polaris drivers and a rubber track. It will cost more than the sled is worth and slows the sled down considerably. It has been marketed as a kit in the past but never sold well. Peter

JDT · Post by **JDT** » Sat Jan 19, 2008 5:01 pm

Was the reason for the lack of performance with the Polaris kit due to the track thickness?
Or was it the OD of the drives?
Todd

JoeRainville · Post by **JoeRainville** » Sat Jan 19, 2008 5:38 pm

Hi Guys,

I should post this as part of my track interchange FAQ, but here is the deal on the Polaris track on a Spitfire or other DD (Direct Drive) Deere sleds:

Good points: The Polaris track that fits is off their DD Cutlass, SS and Star line up. They all used a 2" drive lug pitch like the Deeres. I have to check the length of the available tracks, but I am not sure how close to 116" you can get.

To use a Polaris track, you keep the original drive sprockets. That ends the good news.

Bad news: Everything on the Polaris track is on different centers, including the slide rails and drive sprockets. The sprockets aren't too hard to fix, as I think you can just flip them around to widen them out, and re-bolt them to the original holes.

Widening the slide rails out is a major pain. Every cross shaft must be spaced out. There are good ways and not so good ways to do this, but it can be done.

As for speed, the Polaris track is durable all rubber unit. But, as noted, it's much thicker than the original cleated track and will take more power to turn. However, this is a much better choice than removing the gear reduction ratio by using full diameter 2.52" pitch sprocket or what else can be cobbed in there.

At least all Trailfire's and 80-81 Sportfires can be updated to the LF or 82-84 Sportfire track with just a drive sprocket swap.

I hope this helps to answer your questions.
-Rainville

B)
"Tech-Ed"

JDT · Post by **JDT** » Sat Jan 19, 2008 6:24 pm

I assume that maintaining the originality of the Spitfire is not an issue if the track is going to be converted. If making a rider from an otherwise non-operating machine is the goal than I have two ideas.

First... One could move the entire Polaris suspension system over to the Spitfire. This would eliminate the pain of re-spacing the slides. The rolling resistance of the thicker track would remain a drawback but it would be driveable.

or...

The second idea sound interesting to me. Use the track from a Ski-doo Tundra.
139x 15 x2.0. Of course move the rest of the slide suspension under the Spit also.
Than you would need a tunnel extention too but this would look way cool!

I did this with a Scorpion Stingeroo a couple of years ago and it looked great.

Todd

That Girl Racing · Post by **That Girl Racing** » Sat Jan 19, 2008 8:10 pm

I am sure the Tundra uses a 2.52 pitch (maybe i am wrong) . Even 7 tooth 2.52 drivers will not fit in the Spit. The Polaris drivers are from the direct drive sleds. Peter

Liquifire 4/6 · Post by **Liquifire 4/6** » Sat Jan 19, 2008 8:21 pm

The Polaris track swap seems to be the best solution for now, though as stated, the performance will suffer to some degree due to the stiffer all rubber track. The problem with this (at least in my area) is the limited availability of donor sleds and/or tracks. I'm almost certain the Cutlass/Sprint tracks are the same as used on the early (91-92) direct drive Indy Lites and Starlites. These tracks were not the longest lasting tracks either and as a former Polaris dealer, I get lots of phone calls from guys looking for used tracks for their direct drive Polaris sleds. As far as I know, no aftermarket company ever built them. They are still available from Polaris, but the price is somewhere between ridiculous and absurd. So while it's a good workable solution, you may find that is still not necessarily an inexpensive one. I am very puzzled why Kimpex chose to make a track for the Liquifire, but not for the Spit/Snow/Sprint/Trail/Sport series. The Liquifires had good tracks to begin with whereas the cleated design was a short-lived track. On top of that, there were likely 4 times as many 79-84 JD cleated sleds sold compared to rubber track JD's from the same era. So why didn't they make the ones which they could have sold in far greater quantities? Beats me! I wonder sometimes with the increased interest in vintage sleds, if Kimpex may yet decide to build some replacement tracks for the cleated JD's. Probably just wishful thinking, but you never know. Maybe as a group we could convince them to do so if we could somehow guarantee them that a whole bunch of us would buy some? I'd definately purchase 2 or 3 if they were priced similarly to the other cleated tracks they sell for other sleds. Is this a workable idea? If we could come up with an order for 200-300 tracks, does anyone think Kimpex would bite? Excuse my long reply.

JoeRainville · Post by **JoeRainville** » Sat Jan 19, 2008 9:21 pm

Peter,

I spoke to Kimpex about making a rubber 116" track like the LF, but with a 2" drive lug pitch. They quoted me $300,000 for a mold. I tried to find the original tooling the DD sleds rubber belting, after 22 phone calls, I came up empty. That was around 2002.

The only other option I have is custom making 3.29 pitch sprockets the diameter of the DD sleds sprockets. It would be between the 7 and 8 tooth sprockets in diameter. You would need to use 3 of them and an 80's LF track. The added sprocket almost makes up for the reduction in teeth in contact.

This would also require a new hex drive shaft. So far the cost is prohibative.

I have also tried to find out who made the drive sprockets for the failed 2001 Scorpion sled, as it was Direct Drive with custom 2.52" pitch small diameter drive sprockets.

Maybe it will be worth the tooling to make the 3.29 sprockets for the Spit, but since Wanie will never recoup the cost of a snowflap mold, I doubt I would either....

Needless to say, I am still kicking it around. I am willing to make a billet set and a custom shaft to try out a LF track on a Spit. Just haven't got to it yet.

-Rainville

mwking · Post by **mwking** » Sat Jan 19, 2008 11:08 pm

I looked up the Polaris Star/Cutlass track in the Kimpex catalogue, it is a Durado track part # 04-793. It has the required 15" width and 2" pitch but is 110" long which makes it 6" short. So as stated earlier in this thread the need to move the suspension forward to accomodate the shorter track is obvious. Reinforcing the tunnel with some alumium plates wouldn't be too hard, but that still leaves six cross shafts in the suspension that need to be lengthened. I had a good look at the suspension of my '82 Spitfire when I rebuilt it last fall. The rear axle could likely be reused but would have to have new grooves cut into it by a machine shop. Two of the other shafts are in steel sleeves and longer ones would need to be cut, drilled and tapped. You could likely use some bushings on the shaft to center the sleeve back up. Two of the remaining shafts would have to be replaced with longer ones drilled and tapped with the lower shock mount shaft having flats ground in the ends to fit between the rails and two holes drilled through it for the roll pins that center the shock. The top rear spring perch is a 5/16" 10" long bolt with sleeves and washers on it. It should be possible to make up a replacement with some threaded rod and bushings. I'm not sure that the drivers could be moved out without drilling new holes in the drive shaft, but it would be nice.

Pro.
- it will preserve the stock gearing and performance
- it will put a brand new track on the machine not a used and well aged track

Con.
- The sled may not look quite right with the shorter track under it
- quite a bit of modification is required
- The cost of the new track and modifications will likely exceed the sleds value

I'm lucky my '82 Spitfire is very low mileage and the track is in pretty good shape. Still it won't last forever if I drive it and I didn't redo it to just to look at it. If it stays in it's current condition I would probably go through the conversion process when the time comes because it is in good shape and it will cost less to convert it than it would to buy and fix up another sled. But that still leaves a lot of old sleds being parted out when the track goes because restoring a machine with a bad track won't be worth it.