Theme: Suspension – The Comfort Trap

We conclude March’s theme by wondering if the engineering ideal of suspension that thinks for itself is any closer to reality now than it was thirty years ago.

An early active ride Lotus Esprit prototype. Image:sportscars.tv
An early active ride Lotus Esprit prototype. Image:sportscars.tv

Pity the unfortunate suspension engineer, saddled with the seemingly impossible task of reconciling the hugely complex operating range of the motor vehicle against the twin imperatives of providing a comfortable ride for passengers, while allowing sufficient body control to allow for accurate and consistent handling. Under such constraints, the successful melding of conflicting forces acting vertically in ride and horizontally in cornering and steering, can only result in unhappy compromise. Continue reading “Theme: Suspension – The Comfort Trap”

Theme : Suspension – When Independence Goes Wrong

Defying convention and chiselling away at costs can be a recipe for disaster, as one manufacturer who ought to have known better found out.

chassis4c

Cast your eyes over this ‘platform’. If you’re keen on guessing games, you would take in the V-engine perched over the front wheel centreline, front struts, complex looking independent rear suspension, and all round disc brakes, and conclude that it was probably ‘80s or ‘90s, most likely from the upper end of a European or Japanese manufacturer’s range.
In which case you could scarcely be more wrong. The chassis belongs to a British Ford, introduced in 1966, and costing less than £1000 in its basic form. The Zephyr/Zodiac Mk.IV was the first mass-produced British Ford car to feature independent rear suspension. The trouble is, it wasn’t much good. Continue reading “Theme : Suspension – When Independence Goes Wrong”

Theme : Suspension – Hydrolastic Rubbery Goodness

A long time ago the Midlands of Britain were at the cutting edge of suspension design.

Hydrolastic suspension: source
Hydrolastic suspension: source

In 1955 Citroen presented their DS which had a suspension system markedly different from the ones with which drivers were familiar. The British Motor Corporation picked up Citroen’s fragrant gauntlet. Their attempt to improve ride and handling went under the name hydrolastic and they offered it first on the period’s equivalent of a bog-standard family car, the 1100-series (born as ADO16). Continue reading “Theme : Suspension – Hydrolastic Rubbery Goodness”

Theme : Suspension – Swinging On A Star

The missing link, or just missing a link. We consider the much maligned swing axle.

A Spitfire demonstrates the swing axle's graceful poise - image : triumphexp.com
A Spitfire demonstrates the swing axle’s graceful poise – image : triumphexp.com

The swing axle is the first stop when considering how to make the movement of two rear wheels, previously attached to a solid axle, independent of each other. Simply pivot the shafts either side of the differential and have the two wheels bounce up and down, describing an arc around their respective pivot points. It’s a basic system with many shortcomings but, bearing in mind it dates back to the early days of the motor car, when it was patented by Edmund Rumpler in 1903, that is understandable. Continue reading “Theme : Suspension – Swinging On A Star”

Theme: Suspension – It’s A Kind Of Magic

The suspension system is where the car comes into contact with the road and tries to a) keep it there and b) pretend as if the road doesn’t exist. That’s a lot to ask…

1983 Peugeot 604. Image: www.lrm-collection.fr
1983 Peugeot 604. Image: http://www.lrm-collection.fr

…and then get precious little thanks in return from customers or indeed motoring journalists. The former probably don’t know what suspension is. The latter want all suspension to do the same thing, namely to keep fast cars stuck on the tarmac at 145 mph. This conflict is as big as the one facing the suspension itself, which must mediate between the undulating road and the dynamic system that is the car in motion. The other circle to be squared is that of ride comfort versus handling. Continue reading “Theme: Suspension – It’s A Kind Of Magic”

Theme: Suspension – Cheap and Cheerful

What do most modern small and medium-sized cars have in common? Well, nearly everything.

As modern as can be, at the time. Image: honestjohn.co.uk
1950 Ford Consul. As modern as can be, at the time. Image: honestjohn.co.uk

They are almost all front-wheel drive, with the four-cylinder in-line engine in the front. And almost all of them have MacPherson suspension. Prizes if you can think of an exception. In 2004 the market for small cars consisted of the Fiat Panda, Daewoo Matiz, City Rover, Skoda Fabia and Daihatsu Charade (among others). They all had MacPherson struts. Moving to the present day this is still true nearly all the medium-sized cars are so equipped. Continue reading “Theme: Suspension – Cheap and Cheerful”

Theme: Suspension – Not As Good As It Sounds But Still An Improvement

Suspension systems are inherently reactive. One approach to managing the response of the body to road surface changes is adaptive ride suspension. Is it really any different from passive systems?

Mercedes-Benz S 63 AMG (W222) 2013: autoevolution.com
Mercedes-Benz S 63 AMG (W222) 2013: autoevolution.com

In both passive and active systems, the road surface’s variations are the main input to the body and suspension system. Passive systems are designed to build in to the suspension the capacity to absorb energy so that the body movement is controlled and tyre contact to the road surface is maximized. Active suspensions involve the use of actuators to change the height of the body at each corner of the car. This additional mechanism requires the use of variable-rate shock absorbers and dampers. The active ride system needs sensors to Continue reading “Theme: Suspension – Not As Good As It Sounds But Still An Improvement”

Theme: Suspension – Not Quite De Dion

I spotted this on the Suzuki stand at Geneva. It’s the rear axle of the Vitara, the Hungarian-built Poor Girl’s Evoque.

This slideshow requires JavaScript.


At first I thought that it was a De Dion axle, on closer examination it turns out to be a torsion beam with driven rear wheels. Possibly other manufacturers have done this before, but it’s the first I’ve encountered. I’d have expected to find a live axle, or a multi-link or double wishbone fully independent system. Continue reading “Theme: Suspension – Not Quite De Dion”

Theme : Suspension – Only Fools & Horses?

We have a look at the humble leaf spring and ask whether it deserves universal scorn.

Leaf Spring

I’ve always been a suspension snob, especially on the subject of leaf springs, normally referred to by fellow scorners as cart-springs. And indeed, the use of something that you’d have found on a one horse power medieval cart on a 150mph Ferrari still seems as wrong to me today as it did when I was a picky kid and first realised what lurked under those exotic red bodies..

The first car I ever ‘owned’ was a Ford Prefect E93A that I used to drive as a 14 year old around a bit of woodland. Even at the 20 mph maximum it was possible to achieve weaving around all the trees, I still managed to turn it onto its side, a tribute to my recklessness, a high centre of gravity and its very, very basic suspension which stretched back to the Model T, comprising a beam axle at the front and a live axle at the rear, both mounted on transverse leaves. Continue reading “Theme : Suspension – Only Fools & Horses?”

Theme : Suspension – Introduction

The Editor asks is it a Science or an Art?


Motoring history has a select group of people who can be seen as the creators of outstanding suspension systems, among them are Jean Baudin at Peugeot, Richard Parry-Jones at Ford, Colin Chapman at Lotus, André Lefèbvre at Citroen, Bob Knight at Jaguar and Alex Moulton for BMC. But there were far more who didn’t care for, or understand, the subtleties of suspension, notably Enzo Ferrari who seemed to think that its only reason for existence was to prevent the sumps of his beloved engines from scraping along the road. Continue reading “Theme : Suspension – Introduction”