So what is the trick ?

I've got some 16" formula wheels and some Kumho tires. I can get the bottom side on no problem, but the top side I get about 75% of the way and the tire machine just stops. I tried a bar to 'help' the machine but the tire just won't stretch over the lip. I don't want to tear the bead.

Older center post machine, not a rim clamp.

-- Joe

 

I have a tire machine and on certain rims I have to mount the rim upside down?? My machine is NOT center post though... I also have to guide the tire on (pushing the bead toward the center of the rim as it's turning)

Not sure how low a profile tire, but the lower the profile the hard it is obviously? I also don't know if it would help you (not sure where you are from) but make sure the tire is warm.

Up here when the temps drops the rubber isn't as flexible (Northern Canada here)

 

Well, they are a stock size on a formula rim - 245/50/16. The drop in the rim is by the top. The day did start out around 30 degrees but I had the heater running so the shop was maybe 65 by the time I tried mounting them. Maybe the rubber was still too cold?

-- Joe

 

Beat it in with a sledge, i seen this happen and it's just a worn out machine.

 

Lube/soap the **** out of the bead to get it to slide on better. Push down hard on the part you can get under the lip of the rim and keep applying pressure until it slips on. It takes quite a bit of force to rip the bead so you shouldn't have to worry about that.

 

Not sure if you have been able to mount your tires yet or not. But just in case you havn't, at my work we have a trick called the "2 bar trick".

Basically what you do is after you get the bottom bead on and move to the top bead you use one bar to wedge in as leverage to push the tire down (which is what you probably have been doing already) and then you use your second bar and put it underneath the duckhead in the center of it and put it so that it barely catches that lip as well. Then when you rotate the tire you basically are able to apply pressure on the tire that you would be unable to with your bare hands. Hope that helped some, kind of hard to explain with out showing it.