I am just not a fan of them.
I had them on my Bullet and it ate tires.
I drive a lot of winding roads, and just watching them flex is downright spooky.
Even at slow speeds backing into a spot the flex looks abnormal and I think surely must put a great strain on the sidewalls.
I would like to see how many of these "China bombs" succumb to spread axles?
It seems they employ them on longer trailers to allow for more length and smack dab in the center of the trailer, almost like a teeter totter where they can get away with less tongue weight.
Yes, they do good towing straight I noticed, but I drove slowly, 55-60 when I pulled mine, never had much issue with side wind, but then I wonder if I did wiggle would it also go to the sidewalls as well, seems like that energy would have to go somewhere?
My current trailer has the axles behind the center of the trailer, is 5 feet shorter, but has 200 pounds more tongue weight and both trailers were about the same weight and my tire wear after about 10k is spot on.
What say you?

 

I've never had a spread axle trailer but I can see how it could damage tires doing tight turns etc.
I had an 07 Keystone trailer that had the axles behind the center line of the trailer. That trailer was the best towing bumper pull I've had. I didn't even use any type of sway control, only a weight distribution hitch. The further back the axles are, the better it will tow.

 

I agree, but the further back, better tow, equates to more weight on the bumper, and that leaves a lot of 1/2 tons out, so.........
Again, I wonder how many of these "China bombs" are on spread axles, as I think it is safe to say they are pushing the limit to allow lighter trucks to play????

 

I'm a fan of the spread axles. To be quite honest, i wouldn't have bought the camper i have if it didn't have them.

Consider my situation at the time: my primary tow rig was a short wheel base expedition. the camper i found was an ultralight but was 35 ft long end to end. It was a fair bit above what i was shopping for, but the deal was pretty good for what it was. I convicned myself that it would be ok because of the spread axle if i got a better than average hitch. So with the spread axles and a Reese Straight Line DC hitch, i was able to pull a 7,000 lbs 35' long camper on a vehicle with the wheel base of a mini-van. Safely - in all conditions - no worries at all.

So, for situations like that, they are great.

I have not seen the issues that you mention with tires. Sure, they flex - but that's what they are designed to do. more than 90 percent of your miles are in a straight line. I've been to Tennessee, so i know what you are talking about with winding roads. But even on those roads, while there are a lot of turns there is also a lot of straight between all of those turns as well. I just don't see it as a problem. And even if it is a problem, I wouldn't worry about it.

My camper was about 7 years old when i got it. The original owners bought it in Rapid City, SD. Which makes me think it saw use primarily in the black hills of SD. the black hills are probably worse than Tennessee for winding roads. But i got it when it was 7 years old and it still had the factory Bias ply China Bombs. I used them for a couple of years until i started thinking about how expensive a blow out could get. I replaced them at 9 years old in 2018. The new tires i put on were Carlisle Radial Trail HD. I was a bit worried about sidewall flex at first when switching to a radial on the spread axle. I saw the same tire flex you mention on the original tires and considered staying with bias tires just for that reason. But the deal on these radials was too good to pass up ($50 each installed for an upgraded LRD). The Carlisle radials flex less than the bias ply china bombs did, and i couldn't be happier. Those have been on since 2018 and the treads are still nice and square. I do have one tired that has a shoulder that is more rounded than the others, but i suspect that might be an alignment issue on that corner. It's not a concern, so much as it is something that i've noticed. If i wanted to maximize the tread life, i would have to roate the tires occasionally.

So ... that's my opinion on them. They solve a problem, and i think that the side effects are nothing to be concerned about. Most people don't wear out camper tires, myself included. So if the spread axle wears them out faster its not really a big deal. It might even get some people to replace them in a more timely manner saving themselves trouble with old tires. While the spread axle does have a down side, I just don't think it is one to worry about. You are talking about tire wear after 10k miles. My camper probably hasn't seen 10k miles the whole time I've owned it. We camp a lot, but not that far from home.

in short: if you have a long trailer and are pulling with a 1/2 ton - look for one with a spread axle. Generally speaking, your tires are still going to rot out before they wear out.

 

I thought I saw a thread on one of the brand-specific RV forums where the spread axle trailers were having more suspension issues than the non-spread axle trailers. Broken spring hanger brackets, broken shackles, etc. I tried to find the thread again but my Google Fu isn't working.

 

I think they're good to keep a trailer more "forward thinking" out on the road, but agree they scrub a lot of rubber doing tight turns. I already don't like how much a normal tandem scrubs, but a spread axle is definitely worse. Most of my towing of anything with tandem axles is with 3/4-ton or larger, so I'm not as worried about enhancing stability quite as much as the 1/2-ton folks.

Totally agree on the Carlisle radials that @meborder mentioned completely! Quiet, cool, and happy no matter the load and service. I had a set of China bombs on one of my trailers new from the factory. 4,000 miles and they were about worn out, and with any load they always got hot. I put a set of Carlisles on it and after 5,000 miles they still look like new minus the little molding nubs on the tread.

While we're here, I noticed announcements that Carlisle is now Carlstar. They say this is being done to better reflect the name of the parent company yada yada. Just what we need, another tire brand with "star" in its name! Their announcement is here and a screengrab of it is below for if they take the announcement down someday: