M101A1 Diet Program

I've been looking for a tent trailer that's more off-road capable than the 1967 Apache I already have.

The Apache sets a pretty high bar, providing two large beds, almost 7' of standing room, and in a package that weighs ~400 lbs. A solid wood floor means we can use a Mr. Buddy heater and the thick canvas tent keeps us toasty through the coldest nights. When folded up there's a very large storage area.

There are plenty of off-road trailers on the market but they generally suffer in two dimensions: they are heavy, and most use roof top tents. Oh, and they are usually very expensive.

The weight problem is usually from overbuilding/over-engineering, and is frequently compounded from over optioning. For me, I've been very happy coming back to a camp that has two super-comfy beds, a heater, cooler, and a old coleman stove for cooking. I don't need slide out kitchens, 14 gauge trailer walls to contain my sleeping bags, or struts to gain access to my stuff through a heavy trailer lid.

Roof top tents are awesome - but they don't provide enough space to safely run my heater, or enough space for the kids to have their friends over to play (happens all the time), or enough height to stand up to change, or enough space in a pinch to cook on a cold rainy day (extended camping seasons). The Apache has really nailed the space/weight trade-off game.


So what am I to do?


I've already done a Dexter axle swap to an M101A1 so I'm familiar with how strong these trailers are and the weight savings that could be had. I had purchased another M101A1 to switch to an even lighter 3500 lb axle and section down the bed to see how much lighter I could get it when I ran across an old Sears David Bradley trailer for $400. It looked super clean, same owner for 60(!) years and at 550 pounds with truck sized tires and tons of clearance looked like a great foundation.

IMG_5806.JPG

However, upon closer inspection a long-term flaw in the original design had allowed mud to collect in the box frame and the two side sections were deeply pitted on the inside. I have a choice of simply removing the two frame channels and replacing with either channel or box again, or... Maybe I should drop the Bradley box on the M101A1 frame? Hmmm...

While I'm exploring the body tub transplant I decided to remove the old M101A1 body and do a forensic study of the component weights.

IMG_5901.JPG

Here are my findings:

M101A1 Body:
- Floor: 144.4 lbs
- Front clip: 49.6 lbs
- Tailgate: 40.8 lbs
- Left wall + fender: 73 lbs
- Right wall + fender: 70.4 lbs
Total: 378.2 lbs

Tongue/A-Arms:
- Lunette receiver casting + landing leg: 28.4 lbs
- (2) Safety chains and hooks: 11.2 lbs
- Lunette + nut: 17.6 lbs
Total: 57.2 lbs

Axle, Brakes, and Tires:
Removed:
  • 112 lbs each for 9.00x16 military tire and Budd split ring wheel
  • 208 lbs for the axle with drum brakes
6K Dexter axle and tire weights:
  • 69.6 lbs for each 33x10.50 BFG tire (well worn) and steel 15" rims
  • 65.8 lbs for the axle WITHOUT drum brakes
I saved 42.4 lbs on each side by swapping the tires and wheels, and another 142.2 lbs by going to the 6K Dexter axle.
(NOTE: For this new trailer I'm going to use a 3500 lb axle which will be lighter, but I'll add drum brakes for the parking brake feature)

Total axle/brake/tire/wheel weight savings was 227 lbs.



From the above math, I'm estimating to lose ~662 lbs from a 1340 lb trailer for the first round of this diet, resulting in a 678 lb frame + suspension + tires/wheels. Of course it's missing the front coupler and a landing leg, and I'd like to restore the two parking brakes. I'm also unsure if the 1340 weight includes the trailer cover/tarp and the upper wood walls, which are another 100 lbs or so.


This is going to be a winter project so progress will be slow, but I'll post updates as they happen.
 
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john61ct

Adventurer
Trailer parts are cheap.

A DIY (or pay a welding shop) build of a lighter weight version from scratch would not be expensive.
 

jagular7

Adventurer
Cool project idea. Can I assume the estimated frame weight also included the attached suspension?

For an idea on the tub of your trailer, think M416....formulate the tub of the M101 into a M416 configuration - meaning the outer walls are even with the frame at the base, same for the front/rear bulkheads. There will be wheelwells to cover the tires. You could look to expand the upper rail of the tub similar to the M416, but with the external side supports of the walls, probably wouldn't have a nice flow.
Nice on the Dexter axle with parking brakes.

If I ever can get my hands on a M101 again, that would be my project for it.
(Would you mind if I use this weight info on FB on one of my military trailer groups?)
 
Trailer parts are cheap.

A DIY (or pay a welding shop) build of a lighter weight version from scratch would not be expensive.

I'm starting with the M101A1 because I know it's been designed by real engineers and tested exhaustively over 50 years under the toughest conditions.

The frame also uses u channel which needs to be custom ordered if I built it myself. Most trailers are made from readily available box tubing which generally suffers from long term rust issues in wet climates or use cases.

I believe the sweet spot in frame designs is ~45 inches wide at the frame and 7 feet long which includes 1 ft forward of the bed. All I need to do is shorten the M101A1 frame by a foot and retain the rest of the design.
 
Cool project idea. Can I assume the estimated frame weight also included the attached suspension?

For an idea on the tub of your trailer, think M416....formulate the tub of the M101 into a M416 configuration - meaning the outer walls are even with the frame at the base, same for the front/rear bulkheads. There will be wheelwells to cover the tires. You could look to expand the upper rail of the tub similar to the M416, but with the external side supports of the walls, probably wouldn't have a nice flow.
Nice on the Dexter axle with parking brakes.

If I ever can get my hands on a M101 again, that would be my project for it.
(Would you mind if I use this weight info on FB on one of my military trailer groups?)

Yes, frame weight included frame to spring brackets, all hardware, springs, hubs, wheels, tires and shocks.

I'm going to see if I can pull a few spring leaves to soften them up and shave some more pounds. My maximim/gross trailer weight target is 1500 lbs and would like to hit 900 lbs fully loaded for camping.

And yes, please feel free to cross post any info you find useful :)
 
Last edited:
For an idea on the tub of your trailer, think M416....formulate the tub of the M101 into a M416 configuration - meaning the outer walls are even with the frame at the base, same for the front/rear bulkheads.

Exactly what I'm thinking :)

Only wrinkle is cutting off the existing cross braces from the Bradley trailer, but I guess it's only my time and some grinding discs!
 
Why not put a pop up body on your M101A1 frame?

Good question.

I considered grafting another Apache trailer on top, but the frame is just a bit too narrow (assuming current track) or I'd have to move the wheels out which I'd prefer not to. Perhaps there are other pop-ups I should consider (ideas?). My gut feeling is the newer pop-ups (less than 40 years old!) are a bit heavier and would put my base weight including pop-up closer to 1000 lbs and I'd like to keep it closer to 700 lbs.

I'll do some research and post results back here.
 

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