Sunday, 7 October 2007

Wheel and woe

What is the one thing you can take for granted when you sit in the driving seat of just about any car made in the last 100 years? No matter what the pedals do; whether the lever for the gears is on the floor, the steering column or even a series of push-buttons on the dashboard; you can be sure of sitting behind a steering wheel.

Some early cars had tiller steering but a tiller could not always supply the necessary leverage. There was a practical limit to the range of movement available from a tiller which is not present with a wheel. When cars got heavier and tyres grew fatter gearing was used to keep the effort of turning the wheel within reasonable bounds. This had the negative effect that more turns of the wheel were needed so that a driver might not tire of the effort of moving the wheel but the sheer number of turns needed could itself be wearing. Chrysler introduced power assisted steering in 1951 to alleviate the problem but on the whole steering has remained lower geared than is strictly necessary.

It is worth bearing this in mind when reading Sir John Whitmore’s weekend Telegraph column (link above) about steering technique. Sir John contends that many drivers, including advanced police drivers who are supposed to be the best road drivers of all, are taught to steer using an inferior technique. Instead of shuffling the steering wheel, alternately pulling and pushing with both hands he advocates keeping the hands fixed on the steering wheel (usually at “ten to two” or “quarter to three” on the wheel rim). This, he claims, makes for smoother and more natural steering input. He might have a point except that in a lot of cars it is impossible to steer that way for long before you tie your arms in knots.

So why persist in having a wheel at all? We can see that it does nothing to promote control; it does nothing for safety, presenting a considerable hazard in accidents; it obstructs the view of the instruments and the location of ventilation outlets. When badly located she simple fact of holding the arms outstretched to hold a wheel can make a long journey tiring. Far better to have a couple of angled grips either side of the driver’s seat which follow the natural rotation of the wrist. Whether or not he realised it, Sir John has highlighted a fault that afflicts every car whilst passing un-noticed by nearly every driver. It is a matter that ought to demand immediate attention.


David Wilkins said...

I think the switch to power steering has meant cars do now have rather higher geared steering than before. Two pre PAS cars I can remember had 4.5 turns lock to lock (non-PAS Peugeot 504) and at the other end of the scale 3.5 (the original non-PAS Peugeot 305). With 4.5 turns, you can see why shuffling might have been thought the best method (actually, quite like it from a control point of view still).

I think Saab had a hairy version of the 99 Turbo that had 2.5 turns and no PAS - a home multi-gym would probably have been a better idea.

Fourwheelsteer said...

I must confess that I think shuffling is still relevant to road driving. But I remember hearing about the high-geared power steering of the early Rover SD1, Citroen SM and CX and NSU Ro80. I don't think anyone makes steering like that any more.

In the MGB you could keep a fixed grip on the wheel; it was fast enough but so heavy a strong grip was necessary. I wonder whether people had too much time to get used to low-geared steering so that responsive steering is now criticised as twitchy.