8.5 x 20" tires

[Geoff Weeks]

Anybody have any spec's on these? I have some and can find no info on them at all. They are post WW2 (nylon cord) and I would guess early 60's B.F. Goodrich "Silvertown" Highway express

 Smaller in dia and narrower than a 8.25 x20" tire so goes against the normal size nomenclature of tire sizes

[mowerman]

I think I have at least one of those on mine that has a variety 10 tires. Every one of them is different.

[Geoff Weeks]

I can't find anyone who has any info on loading or rev/mile. Not even recommended rim width.  no info what so ever. Like they never existed.

[Joey Mack]

As far as revs/mile.. can't you just mark the tire at the ground, and roll the tire til the mark is in the ground, then measure that distance and divide it in 5280.  

[Geoff Weeks]

Yeah I could, but I am really more interested in the other spec's. I have no load info on it other than the 12 ply rating, no pressure chart to know how much to put in for a given load.

I am running them on the front of the K-7, I have 8.25 x 20's in the rear. That gives me a top end of close to 60 MPH which is all I need. I doubt I'll overload them, but would be nice to know the spec's

 No one has ever been able to come up with any, which is odd in itself. Add to that, the size that doesn't follow the normal sizing. 8.5 x 20 "should" be bigger than an 8.25 x 20".

[mrsmackpaul]

Never heard of anything like that

Maybe some much older tyre place, anyone that jumps on the computer when you ask probably wont be of much use

A tyre place that has been in business since the 40's with the books from them

Maybe ebay for old tyre books may be the go

Finding the right book is gunna be the challenge 

 

Paul

[High Binder]

Geoff, I think I would give Coker Tire Co. a call to see if they have any info. They would know if anyone does.

[other dog]

I saw this in the Wheels of Time magazine, they might know something. I was looking for a different ad that I see all the time for a place that deals in old, obsolete, and discontinued tire sizes. As usual, I can't find it when I'm looking for it.

[Geoff Weeks]

Thanks to all.

To be clear, I am not looking for tires, but for spec's on that size.  Once mine are no longer useable, I will replace with 8.25 x 20 s like I did on the rear. So far my search has not found anyone with the spec's including someone who claimed to search through older tire/rim mfg spec books.

 I just have never come across a tire I couldn't find a spec somewhere. So far I have just guessed at the pressure for the load they are carrying. At the rate I put miles on the truck, they may outlast my lifetime.

 I have yet to see another tire with that size, so if Mowerman does have one, that will mark the 1st time I have seen them other than the set I had.

 8.25 x 20's are getting harder to find, back when I 1st got this truck you could still get domestic radials in that size, now import bias is all there are, and those have jumped in price considerably.

[67RModel]

Sometimes you just have to cut your losses and throw in the towel. The information you are searching for has been probably completely lost in with time. There may be someone out there that has old literature or whatever that shows something useful but trying to find that place or person probably isn't a valuable use of your time...no disrespect. They look pretty crusty and dry rotted anyway. No telling as old as they are if they would still meet the published specs if you were able to find them. Sorry but no way would I attempt to run those at 60 mph on a steer axle. Accident waiting to happen. 

[Geoff Weeks]

The one pictured is in the scrap pile.  I am just interested in finding the info, Truck is a 45-50 mph truck, will do 60 but I don't run it there.

I my lifetime of trucking I have lost 4 steers, two at 70 mph, and never found them hard to control. Granted they were loaded to 12K not 20K floats, but still. Bang! mash the throttle, make sure you have a firm grip on the wheel, guide to the shoulder, while slowing. Don't jerk the wheel or mash the brakes. Never left my lane because of the blow out. Two were tube type, two were tubeless.

 If you wait to react until you feel it, you are putting yourself at a disadvantage. It may be the truck next to you that blew a tire, but I react 1st and then assess the situation.

 I imagine a 20K float would be more a handful, but I never found a steer blow-out to be a death-ride.