15" Marathon Failure

[wbmiller3]

I always put Michelins on my vehicles. I wish they made trailer tires.

[tentcamper]

+2 on Michelin's get about 70-80k on the TV.

Have not seen many complains on the goodyears this year. A few years back it looked like everyone was having issues??? Is it quality control issue, a tire that developed a leak while you were driving and then shredded itself, or is it the signs of another quality problem with the production?

[Padgett]

OK a few mythconceptions here:
"A tire with a load range of D or E can carry more than a LRC"

Well sort of but is more of a side benefit. First this really only has meaning in terms of light truch and trailer tires. Passenger car tires are "different".

Simplifying things a bit "Load Range B" tires are typically 4 ply ("rating", have seen "2 ply, 4 ply rating") thsanks to the joy of advertising). LRC, 6 ply, LRD 8 ply, and LRE 10 ply. What this really means is that they are rated to handle higher inflation pressures:

B - up to 35 psi, C - 50 psi, D- 65 psi, and E - 80 psi.

And the higher the inflation pressure, the greater the load for a given chamber volume 205,215,225 not going into aspect ratios butg generally the lower the aspect ratio the lower the load for a given size.

OK consider a 225x75 LRC - 2150lb @ 50 psi, LRD - 2540 @ 65 psi, LRE - 2830 @80 psi

Now it is not linear but basically a LRE tire inflated to 50 psi will have the same load rating (actually a little less due to heating) as the same LRC tire. That is why inflation pressure is so important.

At the same time at inflation goes up, tire compliance (shock tranferance) also goes up (why passenger cars recommended inflation is less than the max load). So for a smoother ride you may want a larger tire that allows a lower inflation for the load. Also a trailer has no shocks which is another reason you don't want to overload the axle, pounding the stops is not a good idea and why regular balancing is a Good Thing (tire out of balance may also indicate another problem).

So it is all a balancing act (and I like at least a 15% and prefer 25% overdesign).

Which may give a hint as to why I am considering replaceing the 3.5k axle with a 5k.

[Wingedryder]

I'm making mental notes, guys. I'm reading too many incidents with premature trailer tire failure as yet.

Glad you didn't have major trailer damage, but don't think this should be expected on 3-yr. old tires & no known unusual stresses. I'm sure my TM is much to fragile to endure much road trauma!

[Padgett]

Michelin and BFG make a lot of tires of different types and no reason you need a ST (Special Trailer) a truck rib will do just as well. The hard part is finding a small 15 (205-225) in load range D or E. If there were room for a modern 30" diameter tire then there would be no problem, I could even use the same 245/70R17s (2205 lbs @ 44psi) as my tow vehicle.

The problem is the wheel well and axle limitations of the TM make even a 27" tire chancy without a lift kit though with a 2" lift, a 30" tire should clear.

Personally I'd go the other way & mod the wheel well for an extra 2" of clearance.

In fact a bolt-on kit with 5k axle, wheels and tires with better load ratings, & raised wheel wells (just needs a 2" band added, easier than tubbing for drag tires) I'm going to SWAG at $1200.

I have wondered a bit ever since I saw the tag on the side of mine advising tire inflation 5 psi over the maximum. (note the LR C in the left sticker)


ps just noodling a bit but this looks like a likely candidate axle - 3700 lb rating, same spindle, 35 deg instaed of 22.5 degree down angle for a bit more clearance.