Here's a selection of useful defensive techniques for the cyclist from "Self-Protection on a Cycle" by Marcus Tindal (published in the April, 1901 issue of Pearson's Magazine; see link for full article):
Self-Protection on a Cycle
How you may Best Defend Yourself when Attacked by Modern Highwaymen, Showing how you should Act when Menaced by Footpads, when Chased by another Cyclist, and when Attacked under various other Circumstances; showing, also, how the Cycle may be used as a Weapon.
It is a mistake to suppose that all the romance of the night roads is past and done with -- the romance of the merry old days when highwaymen lay in wait for the benighted traveller on every lonely bit of country road, in every wood, on every stretch of waste land. Attacks by foot-pads on cyclists recall at least some of the glamor of the old stand-and-deliver times to the minds of those who read of these highway robberies every now and again in the papers -- though the cyclists assaulted may not look upon the matter in quite so romantic a light!
Self-protection awheel is an art full of possibilities. The cyclist who is a skilful rider, who possesses pluck and dash, who has mastered the elementary rules of defence on a bicycle, and who is armed with a knowledge of how to use a machine to the best advantage as a weapon, may rest content that he is able to defend himself perfectly when attacked under the majority of likely conditions.
Another case: suppose you are standing face to face with an assailant who has approached close to you, and is threatening you with his fists. You have hold of your bicycle, one hand on the handle-bar the other on the saddle.
To protect yourself and make an attack to the best advantage, all that you have to do is to give your bicycle a slight push, so that it falls over on to your opponent; then, without a pause, aim as heavy a blow as may be at his chest or chin.
Sometimes, a cyclist is just desperate:
Not always, however, is it possible to deal with an assailant with such little risk to oneself as in the above case. In desperate emergencies it is sometimes necessary to act desperately, to take desperate risks. Suppose, for example, that you are riding along a narrow track, or path, when suddenly a man bars your way. To turn and flee is impossible; here, therefore, is your best plan under the circumstances. Ride boldly up to your assailant's side, leap bravely from your machine full upon him, and throw your arms around his neck, leaving your cycle to go where it pleases.
You will come upon him with an irresistible momentum, as though you had dropped from the sky, and if you have not sufficiently damaged him when he strikes the ground, you, at least, are on top. Afterwards, when you have dealt with him as you please, it is quite possible that you will find your wheel lying unharmed on the road-side.
Tindal hasn't forgotten the defensive needs of the fairer cyclist:
The last three or four methods of defence that I have described are hardly suitable for the lady cyclists, unless particularly strong-minded and strong-armed! A simple means of defence that may be highly recommended for the use of fair cyclists is the water squirt. This is an ingenious little weapon sold in cycling shops, made in the shape of a pistol, but with an indiarubber handle which holds water, and which, when pressed, will squirt a shower of water for a distance of 20ft. or so. The water squirt is guaranteed to stop an attack from the most vicious dog or man -- and certainly the foot-pad who attempted to approach a lady cyclist, and was met with a douche of cold water, would receive a severe shock that would probably cause him to stand back long enough to allow his prey to escape.
Let the lady rider suddenly back-pedal with all her might, so that she allows the front wheel of her pursuer's bicycle to collide with her own back wheel. The immediate result will be that the pursuer is thrown from his machine, the rider in front escaping with a slight jerk, which will hardly be felt.