Dual Wheel - Tire side wall clearance

[Neil Wilson]

Please see the pictures below. It shows a pair of 6.50x20 tires mounted as duals on an AA. The owner believes the wheels are the '31-'33 design. He says the side wall space is very small and he is concerned that they will rub once the dump body is installed.

So, the question is - what have others experienced regarding the use of oversize rear tires for a dual wheel application? My advice would be to use the stock 6.00x20 tires.

[markp213]

I have those same tires on my '31 platform truck. The spacing is very tight and is a concern of mine as well. I always make sure the air pressure is correct before driving because if it is a little low, they look like they will rub together! Also, the front tires rub the brake rod when turning sharp, which isn't a pleasant sound! The only real advantage is a few miles per hour gain. The sidewalls on my tires are beginning to crack and I will be replacing them with the stock size to eliminate the problems mentioned above.

1931 AA.jpg (448.86 KiB) Viewed 7712 times

[Bob C]

On the dump truck chassis I bought it had 32X6 tires, which I think are about the same
as 6.50X20, with 1/2" spacers between the wheels. The wheels are early 31, not the later ones
with the reinforcing band.

Bob

[Neil Wilson]

Ford used 32x6 tires on the rear when it was a single wheel setup. The very late '30 and early '31 wheels (without the reinforcement bead) have the same off set as the '31-'33 wheels. So, Bob, tell us about the 1/2" spacers between your duals - how are these spacers installed? can standard dual wheel nuts be uses?

[Bob C]

I went and measured the spacers and they had two 5/16" spacers between the wheels. It doesn't look like
it was a very good setup as the home made spacers only left about 1/3 of the thread being used on the
outside lug nuts.

Bob

[DAN CHALMERS]

Hello all,
wow !!!!. I just returned from NY and Neal, it looks like you took pictures from my shop. Even the truck. just sprayed the fenders etc. black and cab ford red. haven't mounted cab yet maybe tomorrow. that dual wheel set up is exactly like mine. about an 1/8 th inch on ditch side and strong 1/4 inch on drivers . I bought the 6.50 because there was no guarantee when 6.00 would come in. For general around town . I'm not concerned about rubbing or heat. I had a pair of 6.00 for front, and a 6.00 good enough for spare. Getting to the point where I have got to learn how to post pictures.Also picked up all the metal to completely build a new dump body. Do need to figure some things about mounting the gear box and figure the rollers and shafts for the roller and track system. I am convinced it is a Detwiler and not much info yet.Am going to have to get back with Keith and see what he may have for detailed info. Sorry to drag on.
ARE the spacers cut out of old wheels? I have a couple I thought I would use for that. Dan Chalmers

[vtwinsideways]

Is there a difference in offset between the reinforced wheels and the non-reinforced wheels? If so how much? Thanks. Luke

[Bob C]

In 12-31 the offset was increased an 1/8" and the reinforced wheel was introduced in 4-31 but has
the same offset as the 12-31 wheel.

Bob

[vtwinsideways]

So even using the later wheels only results in an added 1/4 in of clearance on a set of duals?

[Bladehorse]

I had the rubbing issue, yet had no issues pertaining to it. I had the dennman tires that are extremely soft, yet I was running almost 1 ton nearly every time I drove it. Occasionally I was flattening out the overloads too(Yeah farmer bob cut a couple of truck springs in 1/2 and made a crude bracket for them to clamp to, the slipper end rode on top of the bracket deal he made to span the service spring.) But after putting over 4500 miles on them with nearly full loads, I had no failures. I did have to patch a tube on the side of the road as my spare got a nail after the screw in the service tire. NOT my idea of fun! So I'm not sure the rubbing issue really is an issue at the speeds we travel. I Was running the full 80# in the rear, and 70# in front however.

[Bladehorse]

ill add that I DID have the rubbing issue with the brake rods, but it was easilly solved my not steering till the wheel stop.

[rollingsculpture]

I had the rubbing issue, yet had no issues pertaining to it. I had the dennman tires that are extremely soft, yet I was running almost 1 ton nearly every time I drove it. Occasionally I was flattening out the overloads too(Yeah farmer bob cut a couple of truck springs in 1/2 and made a crude bracket for them to clamp to, the slipper end rode on top of the bracket deal he made to span the service spring.) But after putting over 4500 miles on them with nearly full loads, I had no failures. I did have to patch a tube on the side of the road as my spare got a nail after the screw in the service tire. NOT my idea of fun! So I'm not sure the rubbing issue really is an issue at the speeds we travel. I Was running the full 80# in the rear, and 70# in front however.

hey bladehorse thats a lot of traveling thanks for the report!!!

[bud valerius]

I have a Budd wheel that I believe was dated 1937 , the offset is 1 1/4" more than the AA wheel , that would solve the rubbing problem . It could only be installed on the outer rear . I noticed that something wasn't right when looking at the front of the AA it is mounted on , it looked like the front of the truck was offset .

[Reds34]

That's funny that it may be dated 1937. In '34 they went to the floating axle so the bolt pattern changed. Maybe it was an aftermarket item for bigger tires? Does the rim itself appear to be any wider?

Red

[Bob C]

I've got a wheel like Bud's. It's dated 5-35 the offset is 1/4" more than the AA wheel and 5/8"-3/4" wider.
The center hole and lug pattern is the same as AA.

Bob