FORKLIFT AMERICA'S FORKLIFT DIGEST
Cushion Tires on Asphalt
When I first moved into my place in Bridgeton MO, the landlord was all to accommodating to install an asphalt ramp for us. It was fall and the leaves were turning brown. The winter came and went and we started noticing huge cracks along the ramp. As summer progresses we began to see the bottom of the ramp starting to crumble, and huge chucks started to come off the bottom where it was unsafe for us to use. The Ramp was poured with no sidewalls, and after 6 unsuccessful repairs, we ended up buying a steel yard ramp to use.
My forklift usage is very high, however it does not take long for asphalt to start cracking and for potholes to form, especially St. Louis where the weather freezes and thaws. (It’s a pavers dream location to have a business). A cushion tire forklift average weight is about 9000 lbs give or take a hundred. Figure the average cushion tire’s contact patch (where the tire touches the ground) is a 4″x6″ area.
Pneumatic or All Terrain “tractor” style tires are best used for asphalt. Cushion tires on asphalt is a bad idea. However, the size of the forklift and condition of the asphalt itself is a factor when driving forklifts outside as well.
2 thoughts on “Cushion Tires on Asphalt”
If your math above is how much per square inch of pressure is on the blacktop its wrong. Only a small portion of the tire is touching the blacktop. for rear tires on a small life you may only have 4″x5″ on the steer tires touching the ground. That would be 112.5 lbs per sq inch. making it 2,250 per small area that each tire touches down upon. Same as concept above but front tires are alot bigger than steers, The fronts would use 1/3 of the weight as the tires are wider and there’s more length touching the ground giving you far more surface contact, but remember your loads on the front end not the rear, depending on how much he’s picking up exactly you may have more weight than a even 2,250. I would bet money on it that there is alot more than just 2,250 on the front each tire. I am a mechanic on Hyster’s I work on alot of 330’s, 280’s, 190’s, and 230’s. Amongst other things, hope this helps.
I’m a structural engineer and my first job in high school was as a warehouseman for a heavy timber construction company where I drove a forklift to load glu-lam beams onto trucks. Having that experience, I believe that every forklift is used to its maximum capacity, which from an operator’s standpoint means that the driver loads it up until the back tires are just barely touching the ground, putting the entire load on the front axle. Forklift operators are not rocket scientists and have no clue as to how much load they’re lifting, they just know that the machine can lift it. All the load on the front axle would double the pressure in your calculation. I am currently searching to find out how high the pressure can be on solid forklift tires but haven’t come up with an answer yet. Pneumatic tires on larger forklifts have a typical maximum pressure of 100 psi. I believe the maximum pressure on solid tires can be higher but I may just use 100 psi since I can’t confirm otherwise.