Just imagine taking part in the Isle of Man TT back in the 1920s and your engine starts to falter and lose power , well thers a good chance the Sparking plug could be the culprit . Maybe the plug was starting to get fouled or over oiled by the rudimentary lubrication system of the day , whatever the reason it was time to change the spark plug and be quick about it , after all you had a race to win ! So where should a rider store the all important plug spanner ? unfastening the straps on a conventional tool box would have taken valuable seconds , hence so many racers of the day are seen with a spanner tucked inside his riding boot , where said spanner could be used in an instant to clean or replace the a plug.
Photo, Charlie Dodson flat on the tank of his Sunbeam in the 1929 TT.
Images The illustrated history of Sunbeam by Robert Cordon Champ.
Motorcycling the Golden years a pictorial anthology by Rupert Prior.