Question about flatbed trailers with the rear axle all the way in the back

Why do so many flatbed trailers have the rear axle all the way to the back? The further back your axles are the more weight it puts to the truck. Now in most cases it's split axle trailer that are set up this way, but can anyone give me a reasonable explanation as to why they build trailers like that? Doesn't it limit their weight displacement a lot more than say a normal trailer where the tandems might be father forward? (not meaning the split axles but more specially 1 axle all the way to the back)

Doesn't it make it harder to not overload the drive axles or at the very least the front trailer axle?

I can understand certain types of trailers that also do this like RGN's or cattle trailers needing to be that way due to the design bu I've never understood why they do it to normal flatbed trailers..

 

Spread axles allow for 40k on the trailer axles (no more than 20k per axle) instead of 34k on your standard tandems. The rear axle is all the way back to better distribute the weight. If both axles were farther up it would be way to easy to overload them.

 

Spread axles are way better imo. I have regular tandems on my trailer now, and I carry a piggyback forklift, so I really have to watch my tail weight.

 

The ones you see without tail swing are generally 48’ long

 

I wouldn't pull a regular flat without spreads. Especially with the weights I pull. Besides, they ride so much better than normal tandems.

 

Like said 48's usually have the rear axle all the way back. My co's trailers don't, but we can load really heavy and never get over on axle weights (unless loaded wrong). But another reason is because to have a 40k gross, the spread needs to be 10'2". On 53's they're usually set forward a bit because of the extra length.

 

Cuz spread axles are for the cool kids

 

Stepdecks and rgn's are for the cool kids lol.

 

The 53 foot trailers need the axles forward some or they violate the kingpin to avle rules in California. One company from South Dakota has the 5th wheel positioned over the rear drive axle and specs a deep pin on their spread axle drop deck flatbeds. They get stopped a lot in Ca but the kingpin to axle measurement is legal.

 

A 10 foot one inch two axle spread under the Ravens 48 foot flatbed covered wagon I had is capable of scaling 20K each axle back there. Meaning I can pack 40000 pounds on the back end of that deck and go legally while still at 34000 on my drives and steers cannot be bothered to care what they had on them. It all depends on what coil where on the deck.

For me the BIG stuff is 24 feet inch steel plate rolled coil almost 9 feet high. That goes onto the exact center marker light of my deck. Since the coil itself is 52000 pounds that creates for my midroof M11 volvo tractor a perfect 80000 with a problem of being VERY V E R Y SCARY TIPPY.

How tippy? getting onto 69 or 65 with a fly over ramp marked 25 requires a 8 mph balancing act. At 6 you flop over and fall out of the sky all that way down. At 12 you fall over the other way and all the way down. Everyone else will just have to wait a durn minute.

Most regular tandems loaded to 40000 back there will wag the dog, you all day long. Whip, wag wag wag. But the spreads? They carry it easily. But if you abused the steering wheel you will create that wag, whip etc.