LightShip 4 Axle Weights

[turbopilot]

This thread is a followup from one of my first posts after taking delivery of the LightShip. When LightShip 4 came off the truck for delivery one of the first things I did was measure the hitch weight. That weight was amazing low at 690 lbs. Initially I was happy with the weight because I knew once LightShip 4 was loaded to camp that hitch weight would likely just pass the 10% of the GVWR threshold recommended for towing an RV. That would have been great news because my loaded F-150 PowerBoost has a relatively small useful load of 1,250 lbs. The higher the hitch weight the less that can be carried in the tow vehicle.

Ben Parker, on the other hand, did not think that hitch weight was good news because the LightShip chassis engineers thought the LightShip suspension was setup to deliver an empty LightShip hitch weight closer 820 lbs. A week after delivery I measured LightShip 4's individual wheel weights to see what was going on. I discovered that LightShip 4's front axle was carrying 1,812 lbs more weight the rear axle. I told Ben about the numbers and his immediate reaction was this needed to be fixed. Several problems surface when a tandem axle trailer has too much weight on one axle. The biggest problem for LightShip 4 was that both front tires were running just under their max load rating of 2,400 lbs. Industry practice is to design wheel weights to be between 85% and 90% of tire load ratings.

Long story short, Ben dispatched Ryan and Zack from Denver with a new axle to be installed in my garage this past week. LightShip axles use a torsion suspension. Depending on how you clock that suspension you will achieve more or less down force on the wheel axles. We discovered my torsion bars were not "clocked" right leading to insufficient down force on the rear axle. Here are the torsion axles.

Here is the new axle:

And here is the original axle:

You can see one axle is "clocked" at about 12:30 while the replacement axle is around 2:30. With the new axle installed you can see how both axles are clocked with the rear axle touching the ground first before the front axle. All of this moves more weight off the front axle to the rear axle and also to the hitch.

Here are the old and new tire weights for LightShip 4. You can see the large swing in axle weights before and after. 1,800 lbs was moved off the front axle to the rear axle along with 70 lbs moved to the hitch. Now each axle shares the load 49% and 51%. This is the design specification for the LightShip.

This will not be an issue for future owners. Just one of those things that happen early in a production run. I really appreciate the heroic effort of sending a two man team from Denver to Arizona to swap axles. LightShip 4 is fully instrumented and sending a lot of data back to the mother ship as I continue my exploration of the vehicle. We plan to head off for a long camping journey in the next few weeks continuing to build mileage on the rig.

Next public appearance will be a reveal to our local RV club in 10 days. The area where I live has been buzzing with sightings of the LightShip around Prescott, Arizona. The first and most common question I get from people who see the LightShip for the first time is "what is it?". An RV is typically not their first guess.