Axle question

some thoughts on why not....
gear cogs designed to operate one way
as are any locking arrangements etc etc etc

Think of it like this...

You are in your yard, pushing an empty wheelbarrow, just high enough so the 2 legs don't hit the ground. You come across a large bump, or garden edging you have to get over, no big deal.

Now, try holding the handles of your barrow really high, like at chest height, or higher, and try to do the same thing...

It's all a matter of where the axle is in relation to the intended travel, in engineering, it's called... moment.

I broke a swing arm on my Yamaha 250, because I landed after a weapon jump, and the bike was still to upright, the load just went through the whole arm.

Cheers

Wolfie

In laymans terms....

Your bus has its springs connected to the dip in the axle. The weight of the bus keeps the axle in a "u" shape and stable.

If you invert the u to an n with the wheels lower than the weight on the axle, the axle will try to invert itself to its more stable "u" form with any minor forward/backward motion of the axle. The leaf springs will end up looking like a lying-down s shape.

To give an example, get a piece of wire (old coathanger), cut a piece and shape it into a similar shape to youraxle (a Greek Omega shape). Now place the two straight bits (representing the wheel hubs) on two books with a gap between them and you will see the u fall through the middle and hang there. Now place your fingers on the bottom of the "u", apply direct pressure downwards and try to get it to swing (the harder you push the more stable it is, obviously don't push so hard as to bend the wire).

Next, lift the "u" to form an "n" and gently hold it there by the "axle" (bit on the books). Now apply the same sort of pressure that you did previously. You will see that it does not take much to get it to invert to its "u" shape again, and that you could not stop it by the axle. This represents the twisting load that would be applied to your springs turning them into the aforementioned "s" shape, and explains why without anything being added to your suspension the system would not work. The initial fwd/bkwd movement of the axle to get it to go off center could easily be applied by bumps in the road, braking, etc.

In short the system is unstable...heed the advice of those that you have spoken to.

Well, it's got nothing to do with the "U" section swinging to the lowest point. Why then to M.A.N trucks use a straight axle beam? The reason you cannot invert the axle is because of a suspension geometry setting called "King Pin Inclination", where the centre line of the king Pins is canted over, not verticle. So, obviously if you reverse the axle you reverse the angle of the King Pin and you would not be able to hold the thing on the road. Full stop!