Leaf Springs Puzzle

[Kevin]

Just been asked a good queation that I can`t answer.
What is the technical specification/theory behind leaf springs.
Are they really a black artform, how is the specification arrived at , because how are the minor ones calculated ? when compared to Escorts & Transit with single leaf springs.
This has occured because of the problem with speed bumps causing different bottoming effects on the saloons whereas on the Traveller it causes a hopping effect.
If you put the Traveller springs on a saloon with the lower 2 springs removed does this help, as the Traveller springs are of a heavier and longer construction (no I did not realise this)
Has anyone any suggestions or know where info can be found

[Cam]

The traveller springs are not longer, all Minor springs are the same length. The saloon (late) has 5 leaves, whereas the traveller as 7 making for a harder ride and a hopping effect when unlaiden and going over speed bumps. I have traveller springs on the back of my saloon to harden the ride, and they seem to work fine. It all depends on what you want, smooth ride or better handling. Also, I think that the late commercials had 8 leaves.

The escort and transit springs are thicker and wider and so don't need multiple leaves. They are also a slighty different shape (I think) which means that they don't deflect linearly (the reason for the Minor's multiple leaves which get shorter towards the bottom).

[Willie]

I changed my early 7 leaf springs to later type because
I didn't enjoy the hard hopping ride.....I much prefer
the softer ride,and with rear telescopics am well satisfied
with the road holding. This is on a convertible, I wouldn't
advise fitting the 5 leaf springs on a traveller if you expect
to load it up regularly....that's why they fitted the stiffer
type in the first place. As stated the springs are exactly
the same length, BUT THEY ARE A DIFFERENT THICKNESS so
removing two leaves would not give the same effect
as fitting a proper 5 leaf spring.

[Kevin]

What is the technical specification/theory behind leaf springs.
Are they really a black artform, how is the specification arrived at , because how are the minor ones calculated ?

Does no one have any idea

[57traveller]

Not exactly what Kevin's after but some info. at
http://www.infodotinc.com/basae/205.htm

Continue to "next" pages there's also stuff about steering, torsion bars, ball joints etc.

[Innovator]

Race Car Vehicle Dynamics by Milliken & Milliken (£70) has calculations for leaf spring rates.

How To Make Your Car Handle by Puhn has approx equations for calculation.

John