Motorcycle
Riding Techniques
©
2002 - 2008, Raymond Wood
Two factors which should be computing away in your mind is:
1) How fast am I traveling
2) The distance I need to stop
We know that for most people to do something about a hazard we use both "thinking" time and "reaction" time. Thinking time is the time during which the brain recognises the hazard and decides to do something about it. Reaction time is the time it takes to actually implement the action the brain has decided upon.
For most of us, thinking time is something slightly less than a second but lets use a second for our calculations. We can see now the distances we travel at various speeds while we are just "thinking" about the hazard. Likewise, let us assume that "reaction" time is roughly a second then double the distance you have travelled while "thinking" about the hazard.
At 60mph / 90kph we travel roughly 90 feet of "thinking" distance before we react to the hazard perceived. Add an additional 90 feet of "reaction" distance while we implement the evasive action decided upon. Combine this with the stopping distance of your bike and you have the total distance it will take for you to come to a halt. Say it takes your bike 200ft to stop at 60mph / 90kph then you have a total distance approaching 400 (90 + 90 + 200) feet that you will travel before stopping.
If a hazard is likely to occur in less than 400ft then you are traveling too fast for the conditions of the road!
For UK riders to easily remember what the ft/second is of various speeds, simply multiply mph x 1.5 for a rough guide. ie. 60 mph x 1.5 = 90 ft/sec. The ft/sec travelled in kph vs ft/sec is rougly equal ie. 60 kph = +/- 60 ft/sec