Hello, I have a question concern

[bootlegend]

Hello,

I have a question concerning rims and the increased tire capacities under creep and stationary load conditions. I need a rim that will carry the maximum load that the tire will carry. It will be mostly stationary, sometimes creeping, but the distance is always very small, maybe 150 feet per day, on a concrete pad. For example, a 445/65R22.5 tire I'm looking at has highway ratings of 12,300 lbs at 120 psi. However, using 105% increase for stationary loading (adding 30 psi) gives a possible carrying capacity of 25,215 lbs. A typical 22.5x14.00 rim is rated for a max load of 12,800 lbs and 125 psi. How do people take advantage of the allowable increases for tires? Reinforce the rims? Or are there manufacturers that make rims that will handle loads like these?

Thanks in advance.

 

[GregLocock]

I think reinforcing the rims is unlikely to be a complete solution. A typical wheel design is highly stressed around the wheelnut area, and I have also seen fatigue cracking in the disc and the welds between the disc and the rim, in some instances.

Having said all that, if the rim doesn't burst apart, and 25 psi seems unlikely to do that, your wheels won't see many cycles and won't see the dynamic loads that a road wheel does (potholes at 40 mph etc), so I'd sit down and stress analyse an existing wheel as it exists and see if it is strong enough.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[CapriRacer]

I agree with Greg, but I think the best answer would be to contact a wheel anufacturer directly.

 

[bootlegend]

The usual rim manufacturer I've used can not provide a product for these loads. I plan on contacting some other manufacturers this week to see if they can help. I was just curious if people routinely take advantage of the increased allowable tire pressures.

 

[CapriRacer]

BootLegend,

Please let us know what you find out. I get lots of questions about wheels, and that is just in my area of expertise.