GERMANS AND RUBBER.

Auckland Star, Volume XLVIII, Issue 113, 12 May 1917, Page 11

GERMANS AND RUBBER.

SUBSTITUTE ON THE MARKET. The scarcity of rubber and the partial commandeering of rubber bicycle tyres have caused a number of substitutes to appear on the German market isays the "'Scientific American"). The substances used are steel wire, leather, wood, prepared canvas, and combinations of these substances. Cyclists will be interested to learn to what straits the German cyclists are put to replace their pneumatics. The first substitute to appear was a tyre made of steel wire, about 3-16 th in thick, which was made up into a very close coil, the two ends being welded together so as to give it the proper shape. Besides the laet that the price is high, the steel coil wire has the additional objection that it cuts into the pavements and rattles considerably when in use. The latter objection might be overcome, it is said, by placing a layer of felt between the rim and the tyre, but this would increase the price. Wooden tyres have been used with some success. At least three different types, of which wood is the main part, are sold in Germany. In a few eases the tyres are made of a single piece of wood. Sectional wooden tyree also have appeared on the market. One of these is composed of 47 parts. These are 12 wooden tyre sections of three different kinds, 12 tin plates, 12 screws, 10 connecting pins, and a thumb screw. The tin plates are used to secure the sections to the rim, which must be of metal; the ecrews to attach the tin places to the ends of the sections; the connecting pins to hold the section together, and the thumb screws to put through the valve hwe In the rim, and thus tends to attach the tyre more firmly to the rim. In order to give satisfaction shock absorbers in the form of steel springs must be attached to the fork of the front wheel when wooden tyree are fitted. A third wooden tyre which is extensively advertised is said not to be meeting with great success on account of the price. This is made of one piece of wood, the outer surface of which is covered with a small strip of leather. Between the under surface of the tyre and the rim several steel springs are placed, with a view to eecuring elasticity. In addition to this, large steel springs are attached to the front aDd back forks. The cost of this outfit, including the two tyres and the large springs, is about 35/. Several leather-covered and canvas-covered tyres also are on the market. These are eolid, the outer casings being of leather or prepared canvas, and the inner part consisting of wood and other substances. To make the tyre more durable small pieces of steel are often affixed to the outer or wearing surface. The prices for products of this class vary. One fairly good leather-covered tyre retails at 47/6 and another at 69/6. The tyre that is said to b,avo the strongest claim to being a real substitute for the rubber articles is composed of two parts, corresponding to the former inner and outer tyres. The inner

part, which is most important, is solid I and is covered with cloth made into the shape of a tyre. The tube is filled with ! a preparation resembling rubber. The ■ outer tube is composed of prepared can- ' vas, and is said to have very good elasticity, so that it can be used without springs at either of the forks. The price for a set of these tyres is 51/6. Tins will doubtless tend to restrict their use. • The most practical tyre from the point of view of both price and service seems I to be the sectional wooden tyre. ; 1 I