Thread: Tandem Suspension Concept

Originally Posted by roverrescue

Absolutely Ben,


Bill, I would still be interested to learn how you would propose the axle to outer leaf pack connection in a camel back setup. Solid attachment to longest leaf or to multiple leafs thus limiting interleaf sliding.

Steve

Google can be bloody frustratingly useless at times. I googled and read 30 odd pages of crap on Mack Camel backs to try and findout exactly how they attached the ends of the springs to the axles. It would appear that the ends of the main and second leaves are bent down 90 degrees with a gap between them and these ends sit inside slotted eurathane or rubber isolater bushings that fit inside so called spring boxes at the axles. The only interesting information I got was that for offroad tipper work, Mack owners preferred Camelback suspension to airbags,They claimed the bags were too slow in transferring air from leading to trailing axle and vice versa for proper loadsharing articulation, citing issues of broken diffs and bent axles in addition to poor traction and poor offroad ride as negative side affects.

Instead of clamping the ends of the springs, how about just bolting a spring with standard bushed ends to the axles and use a single upper link to control braking torque ?

I personally can not see the point in single axle boat trailers. They may be ok on road, but with a boat there is too much overhang for offroad.
Bill.

Originally Posted by wagoo

...

I personally can not see the point in single axle boat trailers. They may be ok on road, but with a boat there is too much overhang for offroad.
Bill.

Tandem axle has the advantages you suggest and allows for more redundancy, however is a lot more weight and rolling resistance to drag around. In my case it also means the difference between brakes and no brakes.


Steve - I have an idea. Instead of the pivoting leaf setup, how about a solid (pivoting) connection between the axles with an (air)spring/shock either end. You could space the springs and shocks up the same as your design. If you use air springs they can be linked on the same side so they can pivot freely.. (clear as mud?)

Originally Posted by isuzurover

Tandem axle has the advantages you suggest and allows for more redundancy, however is a lot more weight and rolling resistance to drag around. In my case it also means the difference between brakes and no brakes.


Steve - I have an idea. Instead of the pivoting leaf setup, how about a solid (pivoting) connection between the axles with an (air)spring/shock either end. You could space the springs and shocks up the same as your design. If you use air springs they can be linked on the same side so they can pivot freely.. (clear as mud?)

A solid beam pivoting off the chassis would transmit excessive shock loads to the chassis when both wheels on the same side strike bumps simultaneously. Unless the airbag interconnection transfer hoses are large diameter ,at high speed they might end up behaving similar to separate units, just like the Mack tipper operators discovered when comparing Macks Camelback and AirRide options.
Bill.

Ben, why would it mean the difference between brakes and no brakes?

weight.

This is one suspension set up I think is worth looking at.
Simple, uses one spring and while it will not give out right long suspension travel in a up and down form with load ( I think that would be a good thing for staibility), It will allow good movement of both axles to follow the ground off road.
Could be used with rubber or air bag.

Originally Posted by 101 Ron

This is one suspension set up I think is worth looking at.
Simple, uses one spring and while it will not give out right long suspension travel in a up and down form with load ( I think that would be a good thing for staibility), It will allow good movement of both axles to follow the ground off road.
Could be used with rubber or air bag.

With rubber springs that is the Mitchell suspension developed by Bob Mitchell, a former Sandgroper, who designed and prototyped this whilst a development engineer at White Motor Corporation of Australia, late 1970's. He had been playing with the idea for some time before he moved over to Brisbane to work at White. Needs shock absorners as there are no multi leaf springs to provide dampimg action. Also need a means of retaing the sring units in place. Bob used long bolts down the middles. Also requires lateral control by Panhard rod, Watts linkage, A-bracket, etc.

Yes!!!

This is the one I was talking about way back at the start, except I was thinking that it had a single pivot at the time. I thought this was an ARB designed suspension used on the mil tandem trailers????