Options for 8.25 x 10 Tires

[horsa]

I guess Mule tires would fit the rims based on the measurements. Think they stand up slightly higher from checking specs on one of the mule sites. What I'm still searching around for is an ATV or small tractor type tire with the solid chevron lugs. Several look similar to the originals but the better looking patterns don't seem to be available in the 8" width with 10" rim.

Has anyone out there successfully used Mule tires or other agricultural patterns on a 6-pdr rim?

For the towed mortar, they first used the same wheel and 16" tire found on the airborne trailers. I've torn my wheel hubs down to see if it was adapted for the 6-prd rim but they apparently used a new hub when they switched the tire patterns out and adopted the 6-pdr rim sometime in 1945 so that kills the option of going back to an airborne rim and tire for lack of functional hubs that will interchange.

[David DeWeese]

Hi,
Don't know if this is any help, but Carlisle makes a 7.50-10 that is fairly rugged. Sidewall shows "Industrial All Purpose, tube type, load range E".
They are 8-ply tread and 4-ply sidewall and are highway rated for 1700 lbs each IIRC.
I use these on my ATV trailer....bought locally.
Thanks, David

[horsa]

Appreicate the lead and shots of what the Carlisle tires look like. I'm still holding out a bit for a wartime military or implement tread but I know they used a lot of civilian road tires as well. Not many options for the small and wide sizes.

[Gunner]

Hi Dave:

I have the same headache with my 6 Pr. Aircraft tyres are actually what the originals were based on! I have been using mule tyres for several years and have gotten a lot of milage out of them... I'm going to order two new ones in the spring to do a tyre swap... the old ones are starting to show canvas after 12 years!

I recently found a homemade trailer using a 6 Pr axle. It had a 6 Pr tyre on one side and an aircraft tyre on the other. The 6 Pr tyre popped when 30 PSI was added... too bad as it had lots of tread on it but clearly no sidewall strength left.

I may see if I can find used 8.50x10 aircraft tyres. I know that they have to replace them after so many cycles even if they still look good.

Cheers! Mike

[horsa]

Used would be the way to go with aircraft tires since they are 10 ply and would still last a long time with something lightweight that was towed. But like the U.S. NDT patterns, they just don't seem right to me.

Attached is a shot of an off-road forklift tire I'm considering. It's for a 10" rim and the section width is 7.9 so would be pretty close to the wartime lugged tires. Less than half an inch off in expanded width so not all that apparent. And while they are also not correct, they project a closer look and feel to the heavy wartime tread I think. Cost is comparable to the modern civilian trailer tires. The inner rim width of the 6-pdr/towed mortar is 5 inches and these have a recommended inner rim size of 5.5 inches. They make another with the same tread for a true 5 inch inner rim size but the section width is 7 inches which is 1 1/4 inches narrower than the wartime tire. I'm told either would fit with no issues though.

Down side is it isn't a highway tire. Max hardtop speed is only about 30mph. Not sure if it becomes unstable at higher speeds or if it will fall apart. But I can't see pulling artillery down the highway at cruising speed myself so don't consider it an issue.

[Grant Bowker]

I don't think the problem is stability but rather heat buildup causing disintegration. The flexing of the tire as it rolls causes heat. If the heat builds faster than it can dissipate the tire will eventually fail. To reduce the total heat buildup there are choices; reduce the speed (fewer revs/cycles per minute but still a minute to dissipate the heat), reduce the load (less flex per rev/cycle), increase inflation pressure (within limits) to reduce flex, reduce the distance (so heat never reaches the dangerous level) between cooloffs. The tradeoffs between load, speed and distance are well understood in the heavy construction equipment field but apply equally to the highway transport field. Tire makers publish load/inflation tables to describe the allowable load for highway tires at various pressures (they assume we won't actually change speed for any length of time on the highwayso they don't publish for that variable).
The need to get rid of heat also is at least part of the reason tires are lower rated in dual applications than single. With less airflow around the tire it doesn't cool as well.

[horsa]

Sounds like the implement type tire would work out fine then for my application. I'd trailer the load anyway if I needed to take it more than 10-15 miles.