Economy in Motorcycle Tires
Caution in the use of motorcycle tires with a minimum of abuse will result in a considerable tire saving. Tremendous wear on a single spot results when the power is thrown in so suddenly that the driving wheel makes several revolutions before gripping the ground. The proper air pressure must be maintained in the tires in order to obtain good wear. Guessing is a poor method of determining the air pressure and the exact condition should be noted from time to time with a gauge. Ordinarily, a pressure of 45 to 50 lb should be maintained in the rear tire and about 20 per cent less in the front tire, in the case of 3-in. tires. Rim cutting from running motorcycle tires underinflated is the commonest abuse. Dents in the edge of the rims cause undue wear on the tire, the fabric being worn through by the constant rubbing. Bent rims are often caused by insufficient air pressure in tires, the liability to injury being increased when crossing tracks or bumps with an improperly inflated tire.
A Knock-Down Tennis-Court Backstop
By EDWARD R. SMITH
Severe weather soon damages a tennis-court backstop that is built on posts set in the ground, and permitted to remain in place during the winter. The backstop shown in the illustration was designed to overcome this objection, and proved efficient on this score, as well as economical to build and maintain. Instead of setting the supports in the ground, they are set on the ground, and guyed by a system of wire braces. The wire netting is also held taut by wire braces, and the entire rigging is quickly taken down for storage, and easily set up when needed again. The lower edge of the wire is held down by hooks pinned to the ground with tent stakes, making it convenient to unhook the netting when the grass is to be cut around the backstop. The towers are 50 ft. apart, about 14 ft. high, and built up of 4 by 4-in. and 2 by 4-in. pieces of sound yellow-pine timber.
The Backstop is Taken Down between Seasons, and can be Raised Quickly by Means of the Supporting Cables
Foundations of brick, anchored into the ground, were made for the towers. End braces of heavy wire, fastened to the top, and guyed to the sunken anchors at the ground, support the towers against the weight of the netting and wire rigging. This is convenient in setting up the arrangement, as a ladder can be leaned against the end of the tower, guyed securely. To withstand side motion at the top edge of the netting, the supporting wires are carried on crossarms of 1 by 1-in. pieces of wood, 2 ft. long. This rigging is suspended between the towers and wired to the netting. When this is drawn up tightly, the netting is fairly taut. Additional supporting wires, with vertical leaders to the netting, are used to draw up the entire length of the netting tautly, as desired.
The netting extends under the towers, and is supported there by wires. As the netting extends nearly to the end guy wires, players cannot be harmed easily by running into the wires particularly if a white flag is attached to the guy wires, about 6 ft. from the ground. Number 20 gauge wire was used for the supporting cables, and No. 9 for the end braces extending to the anchored fastenings.