Imp with leaf springs vs torsion axle

[Snowcat Operations]

Looks like quite a project, sad to see the Imp got to than level of neglect. You got your work cut out! Good luck!

My thought is it will be easier to rebuild her with all the old harware off than it would be to try and find all the parts needed to get her into stock form. If some of these parts can be used to get a few other Imps back on the snowy trails then she will have done more good than being in stock form. Besides everyone wants one bad ass deep powder cat that has modern components!

 

[Snowcat Operations]

It has been absolute hell trying to find stock rims for my Super Imp! In a few months there will be two new suppliers of rims that I know of. BUT in the field I would like to have the option of getting parts at Napa or some other parts place. Rims and tires have been a pretty big deal.

 

[GSSD06]

Did you move the springs farther apart when you put the wider wheel on your Super Imp? On my Super Imp the space between the springs is about 5" which does not leave any room for the tire to flex without contacting the springs.

Did your tire on the wider wheel go flat because it contacted the springs?

What position did you have the wider wheel on?

I am also worried about the standard Imp/Super Imp tire guide beating up the edge of the rim even if the tire is not flat.

The wheel rim is much closer to the tire guide with the wider wheel.

 

[Snowcat Operations]

At first I had it in the #1 position which I knew was a mistake. It went flat after 12 miles after hitting some moguls that got the cat bouncing back and forth. You know what I'm talking about. The next new inner tube and tire I switched to the #2 position which worked great for 80 miles. But the next morning the tire was flat and it was unable to hold air. It was fine on the trailer when I greased the bearings on all the tires when I got back to the parking lot I took off from. The tires tend to flex down at the contact patch so they never rubbed the leafs even though they were pretty damn close. I did though have to tap a few leafs back inline before I installed the tire. I will slightly move the leafs apart when the new poly filled tire gets back this week. I will also put some washers in to correctly center it in the guides. I would be happier with a good 6 or 8 ply skinnier tire though!

 

[Snowcat Operations]

It went flat becasue the track guides bit into the side wall and inner tube. I suspect the inner tube was pinched between the rim and track guides. BUT all this is an educated guess.

 

[GSSD06]

It sounds like your experience supports what I suspected, the narrower tire cross-section with the 2.5" wide wheels is likely to be more reliable.

I was hoping to find narrow 12" diameter wheels for the 4.80 x 12" tires to use with torsion suspension on the Imp, but so far they seem harder to find than the 8" wheels.

 

[Snowcat Operations]

I too would like the 12" tires! I would even like the 16" better! Have you checked into these? The width isnt an issue if you fill the tires. To me thats the only way I will go.

 

[GSSD06]

I am still concerned about wider wheels whether or not they are foam filled. The 4.80 x 12" tires I looked at have a cross section that is very similar to the 4.80 x 8" tires. My concern is the likelihood that the tire guides will still damage the wheel of a foam filled tire.

I have also been told that if you have a flat, carefully check the tire guides because sometimes the wheel rim will gouge the tire guide and then the resulting sharp edge on the tire guide can cut all the bogie tires.

I am going to start looking for larger diameter wheels and tires, especially ones that have a taller rubber profile that could protect the wheel rim from an out-of-position tire guide.

 

[Snowcat Pat]

We've been working on the Imp bogie wheel problem and we have this to offer so far.

The first three pics are of a 1 inch Spryte Improvement hub, spindle and nuts. On it is mounted a Trelleborg 2.5 x 8 two piece wheel and an Alpine Guide 400/480 x 8 six ply tire and tube.

The last three pics are of a 3/4 inch Spryte Improvement hub with a used OEM spindle and nuts. On it is mounted a Sendel 2.5 x 8 two piece wheel and an Alpine Guide 400/480 x 8 six ply tire and tube.

The wheels are centered between the spindle nut with a spacing of 5-5.065 inches to match the leaf spring spacing and the OEM wheels.

The maximum width of the tire and wheel combo is 4.2 inches at the tire sidewalls which should clear the leaf springs by 3/8 inches or more.

We've made two proto's of each size, and are going into production and will have some pics on our webpage of the finished products with the bare steel painted and the seals installed. We are still working out some of the details concerning the choice of 1 inch or 3/4 inch spindle/hub but for now we will be making both available. The assemblies are interchangable with each other and the OEM wheel assembly, and either wheel will fit on either hub.

We welcome your comments, its all about improving! We have pics of all the parts laid out if it might help. If we've missed something please give a shout.

Much thanks to GSSDO6 for his help and supplying parts samples, and also to Snowcat Operations and bobpierce and pixie for the kick in the behind.

-Pat
spryteimp@gmail.com
208-556-0153

 

[couchloafer]

Nice work Pat!!! now get started on the snow tracs wheel and tire problem..(no more wheels or tires available)

 

[pixie]

That's GREAT, Pat

Do you have a price estimate, yet ?

 

[Snowcat Pat]

We are going to add them to our webpage as a complete assembly for $265.00 each. We are working on getting our supplier costs down, and hopefully will be able to offer quantity discounts as we get them, and a better price for Forum members. The parts we make here in Idaho are a heavy duty steel hub, made from 2 3/8 inch solid bar stock press fit to 1/2 inch plate wheel disc and heliarc welded, then machined maintaining a heavy wall thickness. The spindle nuts are made with a larger seal diameter so the bearings should stay in adjustment much longer, allowing the double lip seals to be more effective. We are planning on making our production spindle nuts out of 303 stainless steel. All of these parts we will offer together or separate. Here are some photos of the 1 inch spindle/hub parts.
-Pat