Bicycling for Ladies / The Common Sense of Bicycling; with Hints as to the Art of Wheeling—Advice to Beginners—Dress—Care of the Bicycle—Mechanics—Training—Exercise, etc., etc.

by Maria E. Ward

The solid tire was narrow, and after a certain diameter of material was reached, the weight of rubber became too great if the tire was made larger. It was found that a certain thickness of material was sufficient for wear and tear and that more surface was desired to grip the roadway, and that consequently the tire should be made lighter. Hose-pipe was tried, and did well; and then experiment succeeded experiment in the effort to produce a tire that would fit, wear well, be light, and give speed and resiliance.

A pneumatic tire is made of a tough, hard outer material to resist wear, a fibrous inner material to give stiffness and prevent stretching, and an impervious inner layer to retain the air. Rubber is a sticky, gummy substance, easily melted at a comparatively low temperature, and becoming hard when exposed to the air and moderately low temperature; it dissolves readily in benzine or gasoline or naphtha, and is insoluble in water. Grease and oil have a peculiar disintegrating effect on rubber and rubber materials, and are most injurious to them. To prevent rubber substances from adhering to each other, they are prepared in a particular way, and feel dry and gritty to the touch.

Tires are made in layers, and double-tube tires have a separate inner tube of impervious rubber to hold the air, and an outer covering of toughened material, that is quite separate and not necessarily air-tight, to resist wear.

The tire must be held immovable on the rim of the wheel. There is all the pull of the weight of the moving bicycle against the surface over which it moves, and the tire must be secured to the rim in such a way as to keep it forced in place. There are two methods of fastening it permanently to the rim,—with cement or other material of that character, so as to make it a part of the rim, as it were; and by clamping it fast. A cemented tire, or indeed any tire of rubber, should never be left in the sun, as the heat affects the rubber and perhaps the cement.

Changes of temperature affect different materials in different degrees, and the different materials expand and contract, working loose from each other until something gives way, with apparently inexplicable results. When two or more different materials are used in construction in this way, this problem will always present itself.

The tire inflated, the impervious inner covering of the tire tube, which is made of a soft and yielding substance, fills the interstices in the outer covering, rendering it air-tight. Should a hard substance then be introduced into this material, and a puncture occur, it is necessary to locate the puncture. This is very difficult to do if the puncture is small, and the substance that made the hole has been removed. Ascertain first that the trouble is not with the valve of the tire if the air is not retained properly. Then test for puncture in this way. Wet the surface of the tire, and note the bubbles that form under the film of water, and the puncture is found.

The inner surface tire is made to resist the air, and is usually of pure rubber. The outer covering is for strength and wear. Rubber may be repaired with rubber easily enough, and the purer the rubber, the easier it is to cement it with a cement made of pure rubber dissolved in a volatile vehicle. Almost any repair or renovation of the tire may be accomplished with rubber material, rubber cement to be used for plugging, and twine or cotton cloth to be used for strengthening purposes. Small punctures require only plugging from the inside; tears and rents require plugging and reinforcing as well. Each make of tire has its repair-kit and directions for use.

The single-tube tire, with its inner coat, is so made that the inner covering will act as a continuous plug. The soft rubber is compressed, and put on in such a way that the air pressure, even if a puncture occurs, will help to close the hole by pressing on all sides around and about it. To illustrate this principle, cover the outside of the tube with soft rubber cement, and let it dry. Then turn the tube inside out. The rubber will be in an active state of compression. Force air against the surface, and it is easily seen how the rubber is crowded if there is any place made by puncture, and how the hole would be closed.

Numberless punctures are made and resealed, and the tire works all right. The puncture that does not reseal must be plugged or patched. Rubber plugs are made in all sizes; and rubber cement, liquid rubber, is put up in collapsible metal tubes, like paint-tubes, with a pointed spout to introduce the cement behind and through the puncture. There are numberless convenient contrivances made to hold plugs, enlarge holes, and to do the repair work neatly.

In mending a puncture, the tire remains on the wheel, and the work is done from the outside of the tire. If the hole is very small, it must be enlarged sufficiently to introduce the plug. The rubber of the plug is very soft and compressible, and the hole should be considerably smaller than the shank of the plug.