Freshly powder-coated 21" wire wheels with new Lucas tyres....what are your recommendations for a good, all round, tyre pressure?
I like 32psi for 21" regardless of wheel or body style.
I have always used 40 to 45 pounds since 1980 when I did not know they were supposed to have 21 pounds.
That also gives me a little reserve for a low leak situation.
I run 32 - 34 in mine. I tried 55 before I learned wire wheels and spoke wheels don't use the same pressure and the old tires I had started cracking like mad, Don.
30 - 35 psi it is then.
Service bulletins, page 487 says 32 PSI for 21" tires.
"It's in the book".
Thanki God I read this post. I got new tires for my 21" wheels and was going to blow them up to 55psi.
After the paint cures, I'll break out the garbage bags and mount the tires and tubes and air up to 32psi?
At $25 a tube, this could have been an expensive lesson.
I've used 35 PSI in mine as they roll a little easier, but 32 PSI gives you a better ride. Your choice and preference.
32 pounds is right.
I like 32 psi. A little more, or a little less is okay for personal preference.
A good rim, that has NEVER suffered from rust, or any other, damage, should be able to handle 55 psi. HOWEVER! Rust and other damage UNKNOWN is a common reality. And it is an engineering fact of life, that the mathematical potential for fracture or explosion goes up exponentially with pressure. Exact numbers are impossible to give, at least without very expensive testing. But on an order of magnitude, at 55 psi, you would have nearly ten times the chance of exploding a wheel than at 30 psi.
Not to worry too much. Unlike the rim explosions of two (or more) part split rims, explosions of drop-center or the wood wheel rims usually do not result in serious danger. While the total force is roughly equal, the two part rims have a big piece of shrapnel to throw (the loose ring). The other type split rims, and the drop-center rims usually (not always) do not throw shrapnel. I have had them blow apart twice myself (modern ones!). A scary moment, but all was fine, and all pieces of steel and rubber stayed attached.
Just a few additional thoughts to ponder.
Drive carefully, and enjoy, W2
The correct pressure for 21" tires on a model T is 27 front and up to 32 rear depending on load.
A model A has shock absorbers (dampers) the correct pressure for an A is 35.
A T with 35 lbs. pressure will have too much tire bounce without shocks.
I have ran the manufacturer's suggested maximum pressure in every tire on everything with tires I have owned so I run 35 psi in the '27 Tudor.
Rides fine and handles fine.
Craig, Maximum pressure is for carrying maximum load at maximum speed. Since we rarely carry max load at max speed, the vehicle manufacture's pressure recommendation would be best. I bet you wear out the center of the tread before the sides.
I'm with Craig, Have always run my tires at Max rated pressure as printed on the tire. Hoping for a bit more gas mileage with less rolling resistance just like 0-20W oil.
Have never had a tire wear problem in the centers but I do rotate my tires often.
Model T's are a bit different but racing in the Montana 500 we run a higher pressure as well.
I've never experienced uneven tire wear.......