TINKHAM TRICYCLE.
The Columbia tandems, which were among the first made in this country, were double steerers, and the two handlebars were connected by rods having a ball and socket or universal joint fastened to the end of the grips. The objections to this style of steering rod was that the bicycle could only be mounted or dismounted from on one side, and that in case of a fall the front rider was always hemmed in on the right hand side between the steering rods. The building of tandems in this country was evidently a difficult problem to the early makers, as is evidenced by the fact that the makers of the Columbia, after having made a tandem for a year or two, suspended making them for two or three years after that. A tandem bicycle must not only be strong, but must be light in weight, and as two riders are rarely matched as to ability, power and style of riding, there must be some universal harmonization of contradictory requirements in flexibility and stiffness.
CONSTRUCTION DETAILS OF TANDEMS.
Nearly all makes adjust the front chain by having the front crank-hanger bracket and bearings made eccentric, so as to take up the slack of the chain, and a few of the makers have adopted this same system at the second crank-hanger bracket, others varying this by adjusting the rear chain at the rear fork ends as usual. The makers who furnish their tandems with the chains both on one side claim that this type of construction is the best because in the event of the frame becoming bent or out of line the chains will more readily adapt themselves to the new conditions. Those who use a chain on both sides say that the power is transmitted more evenly by this method, and that therefore the frame is not so liable to be sprung out of line as where the pull is all on one side of the frame. However this may be, a majority of the makers put both chains on one side, and the makers of the National (who have a combination of both systems) claim that their three-chain system applies the power evenly through the frame instead of on one side, and that this system relieves the stress upon the bearings by making both sides do the work instead of allowing one side to run light, and that the use of three chains overcomes the stress of the usual long chain, and permits the riders to run the chains as loosely as on a single wheel without danger of either chain jumping the sprocket when riding fast. Racing men who have ridden the National say that there is no sway whatever in the wheel, and that it gives a more even and steadier pace than is usual in tandems and is easier to hold and follow. The idler used on the National is an ingenious piece of work, being a double ball bearing, the usual idler in ordinary construction being an open plain bearing on a stud. There is practically no strain on this idler, as the pull of one chain is offset by that of the other; it is not used to hold the chain down, but serves as a sort of loose pulley connection.
WOLFF-AMERICAN TRIPLET.
The only juvenile tandems made are those made by the makers of the Elfin. They are a part of their regular output, and are made in both diamond and combination styles, the heights of frame running from 16 to 22 inches, and the weight from 28 to 35 pounds. The little gears run from 50 to 67 inches. These little Elfin tandems are distinctively juvenile in all their parts, the head, saddles, pedals, handlebars, grips and tubing are all miniature in size, making its measurements as nicely proportioned as a regular adult’s wheel, and the name “Elfin” has been well selected for the product. These little tandems are sold for $50.