Bicycles, Motorbikes and Cars - Leaders Lowdown by John Hunt

 

During my high school years I rode a bicycle about 3 kms a day each way to school from Greenacre to Bankstown, down the Hume Highway. In the afternoon I made a right hand turn from Chapel Road into the Hume Highway opposite the Three Swallows Hotel, when there were no traffic lights at the intersection (and much less traffic than there is today). The only accident I can recall was losing the front wheel on a slippery wooden gutter crossing in front of our house, as I was leaving home one morning.

 

The first motorised vehicle I owned was a 125cc motorcycle, which I bought soon after I gained my driver’s licence. I consider myself lucky to still have two arms and two legs having ridden it for 5 years, mainly around the city. That was before I developed road sense and judgement. Having driven cars, trucks, tractors and motorbikes for about 40 years, I got back on the bike about 10 years ago. Funny thing is that the only serious accident I have had on a bicycle since then, involved a slippery wooden bridge. I guess some people never learn.

 

Braking

 

In my experience braking on a bicycle and motorcycle involves the same principles and skills. Essentially if you want to stop quickly you must apply the front brakes hard without losing the front wheel. You may have noticed that the superbikes have two disc brakes on the front and one on the rear presumably for just this reason. Hard braking on any vehicle involves a transfer of weight from the rear to front wheel(s), at which stage the rear wheel(s) may start to slide due to lack of weight, which is usually controllable. I believe that a bicycle can brake from a given speed over a shorter distance than a car (all other things being equal).

 

One useful thing that I learnt on a motorcycle was that the centre of a traffic lane is usually coated in oil which makes it very slippery after the first rain. This is very obvious when wearing polaroid visor or sun glasses. I usually ride in the left hand car wheel track when the road is wet for that reason. Since losing the front wheel on a slippery wooden bridge, I routinely do not use my front brake for normal braking, particularly if the pavement is wet, preferring to  feel out the surface with the rear wheel first. I recall that Doug Stewart told me on BN Chat several years ago but I took no notice. However as I said emergency braking still requires use of the front brakes, preferably in a straight line.

 

Cornering

 

Cornering techniques for a motorbike and bicycle are almost diametrically opposed. A motorcycle weighs about twice the weight of the rider. I can still picture the MotoGP jockeys, leaning into the corner, hanging off the motorbike with their inside knee perilously close to be abraded away on the pavement. A bicycle on the other hand weighs a lot less than the rider, maybe by a factor of 5 to 10 times. When I got back on to the bicycle I tried to corner like I was riding a motorbike, and leaned into the corner. I always felt unstable and unsafe at speed, so I descended relatively slowly. About two years ago I googled cornering at speed and found two Tour de France riders who offered the same advice on U tube. “Lean the bicycle, not the rider”. This is sometimes described as pushing down on the inside handlebar, which is done by straightening the inside arm which pushes the body up. I tried it and its works. So what’s going on? I believe that the explanation is that when the rider is more upright, the centre of gravity of the bike and rider is over a line drawn between the points of contact of the wheels with the road. That is the weight is located where the rubber hits the road. If the rider leans with the bike, the centre of gravity lies in mid-air somewhere inboard from the line where the rubber hits the road – a very unstable situation. Well that’s my story anyway and I’m sticking with it until I hear a better explanation.