Quote:
Originally Posted by TM Pilot
Dave,
In addition to weight (1870lbs), I consider pressure (50psi) to be a limiting factor on my TM's factory 14" rims. I haven't seen any documentation from Trailmanor or markings on my factory rims that state otherwise. I am also not aware of any 14" rim made by any manufacturer that is limited to 1870lbs yet is also rated to 65psi. Therefore, I'm not comfortable being a test pilot and fitting a 14" load rating D tire filled to 65psi on a rim that is, most likely, limited to 50psi. In my opinion, that's not safe.
No rim manufacturer is going to authorize one to fill their rims over the maximum pressure for the rim. That a tire mounted on that rim can handle a higher pressure is irrelevant. Safety limits itself to the most restrictive component.
Here is one example from a rim manufacturer (see pg. 10): http://www.accuridecorp.com/files/20...4-06-22-12.pdf
Here is one example from a tire manufacturer: http://www.tirerack.com/images/tires...plications.pdf
Rim and tire manufactures both agree that one should not fill a rim (a.k.a. wheel) beyond its maximum pressure.
Lots of TM owners with 14" rims/tires have never blown their tires. Some with 15" rims/tires have blown theirs.
Did you have your 14" Kuhmo's mounted on your TM factory 14" rims or mounted on aftermarket 14" rims when they both blew out 3 years later? What was the maximum psi limitation for your rims? Just curious.
Bruce |
Of course, lots of TM owners have never blown their 14" tires. It's just a matter of odds -- what level of risk are you comfortable with? I had 3 blowouts on 14" wheels (one Marathon, two Kumhos) within a 3-year period, and may others here with 14" wheels were having the same problem, so I decided that if I didn't want more blowouts, I was going to have to make a change. The risk was too much for me. Having a blowout is a near surefire way to ruin your weekend, and worse, can do major damage to the TM.
Yes, I had my Kumhos mounted on my TM factory 14" rims - I don't know what the pressure limit was, but since they were OEM, it was probably 65 psi like yours. The Kumhos had a max pressure of 65 psi, so that never exceeded the pressure limit of the rims. After upgrading to the 15" tires, I did run them briefly at 70-80 psi, but that shook the crap out of the trailer, so now I always run them at 65 psi. And in using the lower pressure, I still have a significantly higher weight carrying capacity than I did with the 14" wheels, which I feel reduces my risk of a blowout. And this change in turn has left me with zero blowouts after 4 years and many thousands of miles.
IMHO, the bottom line is if you can fit 15" tires on there, that's your best bet by far.
I had to put the lift kit on mine, but that was inexpensive ($40), and easy to install (a little more involved than changing a tire, less involved than changing bearings or brakes).
Dave