I just bought a new 8.5x24 ft enclosed car hauler with 5k axles (10k gvw). The price was too low to pass up. Well, it has Tow Master bias tires that are load range D and 4ply nylon tread and 4ply nylon sidewall. I plan to travel 200-300 miles at a time with it so should I put radials on it? Are the bias more prone to blow outs? I hate to buy new tires for a new trailer I haven't even used yet, but I could probably get some money out of the bias plys?

 

WOW, I didn't know they were still making bias ply tires. The design of bias ply tires are fine if you tend to drive straight. The advantage of radials is that there are more plys in the sidewall (at least potentially depending on the brand/model of tire you buy) which keeps more tread on the pavement during cornering. Bias plys are not as strong (this is a relative term since the sidewall plys can be stiffer and bigger than the additional radial plys) on the sidewall since most plys are oriented along the circumference of the tire. I'd be more concerned about the load factor of the bias-ply tires. I believe most radials will support more weight because the sidewall is stronger. My experience has shown more flats with radials and more sidewall blowouts with bias ply tires. That, of course, relates to vehicles - not necessarily trailers. All that being said, I probably wouldn't change them on the trailer until they are worn.
regards,
AJG

 

FWIW the Tow Master tire seems to have pretty good reviews on the RV forums I've been reading for the past month. A local tire guy recommended bias for the fact that if/when they blow they often come apart in chunks, whereas a radial tire will often start losing the tread and the "strip" will beat/tear your trailer apart. My trailer is a 97 24ft Haulmark and I'm on my fourth set of tires and looking for my fifth. Goodyear marathons, and presently Carlisles all D rated. I seem to only get two years out of them even with limited use. I'm going to go with an E rated 15" tire this time around and if those don't last my next investment I will go with 16" rims and tires. I live in the desert and the low humidity/high heat is brutal on trailer tires. I get one blowout or see a separation issue they all get thrown out. Also....most tire manufacturers recommend that if you have a blowout on one axle, replace both tires on that side as you will put an excessive load on the remaining tire that didn't fail. So far I've had NO trailer damage and intend on keeping it that way.

 

bias ply tires run hotter than radials when carring a load and at interstate speeds. Radial ST or ST bias ply [trailer tires] are 65 mph max speed rated. Most folks upgrade to a LT tire for better tire reliability. I think for that size trailer your present tires are 225/75-15 D load range. A LT 225/75-15 D load range tire will be a good upgrade.
JIM

 

Don't sweat it on the bias tires. I have a 12K utility trailer that I just replaced the bias tires on. I ran them for almost 5 years without a single mishap (besides the occasional nail or screw in the tire). I do not baby this trailer at all and the tires get their fair share of abuse. I replaced last fall with radials (Carlisle brand) load range E and honestly, I liked the bias tires better. I think the sidewalls were stiffer, they did not squat as much and were not as spongy as the radials. The radials are good tires, and they seem to track just fine, but next time, I think I'll get another set of bias tires.

 

I was not aware of this max speed rating on the trailer tires. I run mine loaded quite often down the highway at 75-80 MPH. There must be a pretty good safety factor there.

 

Thanks for the feedback guys. I did some searching for LT load range D tires (size 225/75 15) but could not find any. I think I'll stick with bias ply for now. I need to spend money on WD hitch and other misc goodies.

 

Bias ply are great for trailers, and not so great for cars. They have very strong side walls and will support a load much better. They also track very well and do not wander nearly as much, likely due to the fact that the sidewalls are not flexing as much.

As far as tow masters go, they will be the only trailer tire I use from now on. I have used Duro, carlisle, and good years, and the tow masters have always been much better both in wear, trailer tracking, and durability.

 

yeah, its a fed spec for all ST tires as to their construction according to Goodyear web. See rv.net web and look in on the TT/5th wheel forums for lots of bad stories on ST tires/heavy trailers/interstate speeds.
JIM