moving up to 12 " tires

[Bob23]

Mac:
   Aren't those numbers on the tires maximum pressures? I play around with my Tundra pressures depending on if I'm towing my construction trailer or not. I've found I can increase the tire life that way. But I'm nowhere near 50 psi.
   My 23 trailer tires get 50-55 but I've  so little mileage on them that it is impossible to tell if they are wearing correctly. But your "sidewalls needing to be full" arguement makes sense. 
   90! I'd be scared putting that much pressure in any tire, old or new. My fear probably stems back to my wayward youth when I blew up a bike tire at the gas station. My ears rang for days! Funny how you remember wierd stuff from the days of yesteryear!
   Remember that the pressure increases on the road when the tires get warm.
Bob23..checking my trailers tires and pressure.

[wes]

Bob - I routinely run 90 psi. The contact patch is very small on our trailer tires compared to a car or truck tire, so the pressure must be high. With about 3000 lbs of weight, that's 1500 per tire. If the contact area is 4"x4" or 16 sq. in., you need almost 94 psi (hypothetical example). If you underinflate, the patch gets bigger and the heat from friction increases, as does deformation of the sidewall.

Obviously larger tires have bigger contact patches, so need less air pressure to support the same weight. Mine are hilariously small - it seems like a miracle that those little tires can carry that load. But it's been three years of towing and so far no problems.

Wes

[brackish]

    since first posting my question about 12" trailer tires i have been doing some internet research, trying to get a handle on which tire i should buy. it seems that every review i have read regarding ther following brands was unfavorable---goodyear marathons, nanco, towmaster, nankang, and carlyle. most of the reviewers complained about blowouts, poorwear and even damage to their trailers. can anyone here recommend a brand of tire i can live with. this is for my cp16 so i figure i should have a load c at least.

Kind of late, just saw this.  I've got a little over 8 years but probably only about 3500 miles on the original set of Trail America ST bias ply tires.  They are just now getting enough sidewall cracking that I'm considering changing them. 

[Bob23]

Thanks, Wes.
   I stand corrected...I'm always amazed about the things I learn here on the site! Makes sense...my road bike tires ride on about 110 psi.
Bob23

[MacGyver]

Mac:
   Aren't those numbers on the tires maximum pressures? I play around with my Tundra pressures depending on if I'm towing my construction trailer or not. I've found I can increase the tire life that way. But I'm nowhere near 50 psi.
   My 23 trailer tires get 50-55 but I've  so little mileage on them that it is impossible to tell if they are wearing correctly. But your "sidewalls needing to be full" arguement makes sense. 
   90! I'd be scared putting that much pressure in any tire, old or new. My fear probably stems back to my wayward youth when I blew up a bike tire at the gas station. My ears rang for days! Funny how you remember wierd stuff from the days of yesteryear!
   Remember that the pressure increases on the road when the tires get warm.
Bob23..checking my trailers tires and pressure.

Higher pressures are interesting when filling them up, and will definitely cause you to find the flaws easier! LOL
Lower than the recommended will cause more heat buildup and then in turn cause more premature wear. Also (I have heard) that the sidewalls on trailer tires are stronger so by underinflating them they buckle which can cause them to also break apart.
The whole thing about tires is also so interesting......... Everytime I see about people having tires from over 10 years ago or see people come into the marina with deep cracks (mimic-ing the eczema on my hands at its worst) I wonder why I had a perfectly good tire blow on my trailer when I first went and picked the boat up.......

Mac

[kickingbug1]

   just in case anyone wanted to know. i put 5.70 12s on my cp 16 trailer (majic tilt) with no problems. i did have to raise the fenders a bit but that was easy. just unbolt them from the frame and move them as high as the brackets allow and drill two new holes. i havent tried it on the ramp yet but i did pull it down the highway at 70 mph with no problems.

[nies]

The tire size on my org. trailer was 570-8 C and what I have replaced over the years, was told at Farm & Fleet the next size up was 480-12 6 ply ,both are Bias, now I wonder if true..........................any tire guys out there?.........nies

[kickingbug1]

   worked great on the ramp----i didnt notice any difference