Tell me if I am crazy Solar RV Escape module

[j-c-c]

If I have to, but they must have working brakes I suspect, that is the toughest aspect to modulate, ignoring the potential severe tag axle overloading that might take place when traversing a severe driveway dip.

Another solution and likely another can of worms with regulation loopholes, I am not sure the third axle has to be in contact with the road at all or at any time, just that you must have one. In Fla its common to see 3 axle dump trucks empty to have a fourth lifted axle, and when fully loaded many lift the axle to assist in making corners and reduce huge tire scrub issues when turning when fully loaded. Having the liftable axle as close to the rear fixed axle reduces the turning tire scrub issues when liftable axle is in contact with the road, which a bumper hitch location would not facilitate.

[Piotrsko]

There's 2 ways to do a lifted axle: static chained lift where the axle is restricted until the weight involved causes the tires to contact pavement or some sort of pressure vessel instead of springs that you can raise or lower like the followers on a cement truck

[j-c-c]

Need to make a correction:

Fla Statues; Definitions 320.01(1)(b).5 The “private motor coach,” which is a vehicular unit which does not exceed the length, width, and height limitations provided in s. 316.515(9), is built on a self-propelled bus type chassis having no fewer than three load-bearing axles, and is primarily designed to provide temporary living quarters for recreational, camping, or travel use.

Fla Statue 316.515 9a (9) BUSES AND PRIVATE MOTOR COACHES.–
(a) Anything in this chapter to the contrary notwithstanding, no bus or private motor coach may exceed a length of 50 feet, ........

Takeaway, max length with Bus/Motor coach w three load bearing axles is 50', not 45' I noted earlier.

Guess that is my path for a solution here,
Back to the drawing board.

Now I am wondering what the overall effeciency gain might be by adding aero devices less the extra energy to carry and roll another lightly load axle due to added weight, rolling resistance, and air drag.
It never ends.

[freebeard]

...self-propelled bus type chassis having no fewer than three load-bearing axles...

Gotta love legalese. What is even a 'self-propelled bus type' chassis? Microbus? Monocoque coach? Ladder frame school bus? ...that's a big enough loophole for a lawyer to drive a Mercedes through.

This COE bus -- what will it have at the rear? A ramp for the race car? Could you bob the rear end in the conversion?

Take off the bumper and permanently attach a single wheel trailer with a brake. Presto -- an articulated bus.

[j-c-c]

Not sure if a single wheel (caster?) constitutes an "axle", and still will require some controllable braking activation.

And yes, a lowered angled rear floor in last 15'? of the bus, and then removeable storable ramps to get to the ground. The bus has considerable rear overhang beyond the rear axle, which has upside and down in this application, good turning radius, little structure to modify for built in ramp, rear axle has little interference building in the ramp, and are all pluses, biggest downside so far is concern of dragging rear lowered bumper/hitch on sudden steep elevation changes like driveways, etc. Weight distribution is not a concern with this chassis and expected layout/load., luckily.

[freebeard]

Ask a lawyer, get it in writing, put it in the glove box? It's an 'axle' and you could use an electric trailer brake.

The ramp bed complicates any boat tailing. Why do you want it longer, again?

[j-c-c]

To recap, it is a COE flat front 40' bus diesel chassis. 2/3 of roof will be Solar panels, front 1/3 will be viewing platform. I want a very comfortable single person living quarters in front portion. Rear portion will have storage as available and one vehicle, likely a streetable TA type muscle track car, which needs 17'. Car has approx 3' of rear overhang beyond rear axle. Letting that 3' hang over the rear RV bumper gains me much useful living quarters space.

My original plan was when car was secured for transport was to allow the rear car overhang to protrude 3' inside the rear 4' long hollow composite nearly full height "energy conservation device" sight unseen, and fully enclosed.
The Aero device would be top hinged to access and remove the car and become a shade for car Maintenace when car is on the ground, if desired.

Adding a small conventional tag axle is doable, but I'm starting to encroach on rear sided mounted aux genset, fuel supply for genset, existing bus fuel tank, and to be installed fixed interior sloping ramp.

As I'm typing this, I'm thinking I should just design the build with the option of adding a tag axle only if needed by enforcement down the road, and stay with my original plan and build the best looking, most professional easy to assume "approved" energy saving device and take a chance on a $100 overlength fine if it ever gets noticed.

[freebeard]

How high would that three feet of overhang be off the pavement?

[j-c-c]

Not yet finalized, but most of the cars transported will have robust diffusers at least to rear of the car's rear bumper, and will be low as comfortable for max DF, so guessing at the angle with 3' extension past the RV bumper, I say 36" off the ground, car ramp height on RV will be approx 30".
Nothing has as of today been officially located, because the transported car's RV position has been up in the air.

[freebeard]

Over 18" needs a red flag?