I measured the force to debead a tire

[srimes]

I made a press and tested the force to separate my tire bead at different pressures. The results were quite linear! R-squared of .995 means 99.5% of the observed variation is explained by pressure.

@macleanflood I'd say this fits with how easy it is to lose a bead winching sideways in the snow.

 

[lBasket]

I made a press and tested the force to separate my tire bead at different pressures. The results were quite linear! R-squared of .995 means 99.5% of the observed variation is explained by pressure.

View attachment 589315


@macleanflood I'd say this fits with how easy it is to lose a bead winching sideways in the snow.

What size of tire? How old? This is pretty interesting, makes me think of when I did my jeep vs MR2 tires.

Hi lift on the tire and under my trucks hitch, all the Jeep tires came off easy. My MR2 tires were like 16yo and small, and lifted the truck off the ground without breaking the bead. I had to find a different solution lol.

 

[srimes]

What size of tire? How old? This is pretty interesting, makes me think of when I did my jeep vs MR2 tires.

Hi lift on the tire and under my trucks hitch, all the Jeep tires came off easy. My MR2 tires were like 16yo and small, and lifted the truck off the ground without breaking the bead. I had to find a different solution lol.

35x12.5x15s. Fairly old Patagonia. The very 1st one at 0 psi was 1816 lb. I didn't use that data point as I was inconsistent with the speed as I was just learning the process. The other 3 cycles at 0 psi were 1454, 1462, and 1463. Maybe it was the speed, maybe the rubber was slightly fused that made the 1st break higher.

I was mainly looking for repeatability from the test method, and I'm very happy with these results. I geek out on this stuff!

 

[lBasket]

35x12.5x15s. Fairly old Patagonia. The very 1st one at 0 psi was 1816 lb. I didn't use that data point as I was inconsistent with the speed as I was just learning the process. The other 3 cycles at 0 psi were 1454, 1462, and 1463. Maybe it was the speed, maybe the rubber was slightly fused that made the 1st break higher.

I was mainly looking for repeatability from the test method, and I'm very happy with these results. I geek out on this stuff!

Interesting. I could see it being the speed - idk what size press you have but an extra 400lbs from a 20t press due to overzealous pumping seems pretty easy. It is definitely cool to see - wish I measured those oldddd tires to see how they'd compare.

I'd believe this was close to what it took to remove my 33s, the lift on the rear end of the truck had to be under 2000lbs or so or else it'd have gotten lifted much higher.

 

[srimes]

I tested my new tires for comparison.

They come off with a lot less force!