From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Technical explanation of the causes of skidding in motor vehicles.
| Identifier | ExFiles\Box 15\6\ Scan153 | |
| Date | 1st January 1931 guessed | |
| Translation. x728. SECURITY IN MOTOR VEHICLE DRIVING. STABILITY is the great factor in safe driving and lack of it is the inherent cause of all skids. Skidding occurs under unfavourable circumstances even at minimum speeds, the most skilful driver is not immune because the cause lies in the construction of the vehicle. Skidding deprives the front wheels of the vehicle of their directional control, - when the skid occurs the car no longer responds to the steering wheel but is at the mercy of chance. Travelling in any conventional vehicle, one is exposed to the danger of skidding at any moment. Every experienced driver knows that skidding happens precisely at the moment when accurate steering is most vital, for example - a) When the brakes are suddenly applied before an obstacle. b) When suddenly swerving. c) When taking a bend. d) When overtaking in narrow roads. Can skidding be avoided without sacrificing speed and the other amenities of motoring? To answer these questions one must first understand the way skids originate and develop. The Causes of Skidding. When we speak of a skid we mean that a vehicle is travelling with its centre line obliquely positioned to its direction of travel, - that is, it does a turn not prescribed by the steering gear and which cannot, therefore, be influenced by it. This involuntarily turning movement generally covers a much smaller circle than a similar turn deliberately controlled by the steering. In other words the Car turns on its own axis. Now this turning movement is caused by the rear wheels being made to revolve at different speeds by the engine and this difference in the wheel speed results in turn from uneven grip of the road surface or uneven braking of the rear wheels. As the differential which connects the cardan shaft with the rear wheels distributes the inertia moment of the shaft to the wheels in inverse proportion to the resistance, it follows that the wheel with less surface grip, or less braking, is made to revolve at a greater speed than the one with more grip or braking. | ||