LIBERTY SPROCKET.
We find in one of the British trade journals a mention of a “spring chain,” but there is neither cut nor detailed description. The maker claims that by inserting a dozen or so of his spring links in any suitable chain “it will be made to run as easily and smoothly as a leather driving band, and that it may be adjusted so tightly as to practically do away with all slackening on top, so that every ounce of driving pressure applied to the pedals will be reproduced on the rear sprocket wheel, thus getting rid of all backlash and consequent friction and waste of power, even when ridden over the roughest roads and by the most inexperienced pedallers.” The editor thinks it impossible, without some dynamometer test, to say whether there is any gain in driving ease, but after having one of the chains in use for a good many months he can bear out the claim of smooth running, and has found that it can be run on a tighter adjustment than the usual chain; so “it certainly seems to be satisfactory.”
CRESCENT
CHAIN ADJUSTER.
The [circular chain] is another peculiar English device, and is pronounced by its maker to be the best and easiest running, wear-resisting and cleanest he has ever tried. His claim is: “The circumferential speed of the block chain is in excess of the corresponding speed of its chain wheel teeth, hence the contradictory friction between tooth and block. The circumferential speed of this chain and its wheel are similar; entirely does away the frictional contact between the teeth of the chain wheel and the chain blocks.”
His first statement cannot possibly be correct so long as the pitch line of the sprocket and of the chain correspond, as is the case with any reasonably good fit. His chain consists of simple and uniform links, turned from the solid and joined by rivets. It suggests the old chain of the chain pump, and, of course, requires a peculiar sprocket.
The Tacagni standard pivot or rivetless is a recently offered English article. It is light, weighing 7¾ ounces, against the usual 14½. Less friction and greater strength are also claimed for it, the maker offering the report of a testing firm that the elastic limit of the sample used was 900 pounds and its breaking stress was 1440. Of course, a special sprocket grooved in the rim must be made for it.
THE REMINGTON CHAIN.
The chain brought out by the [Remington] people for their $75 model suggests the Tacagni, but is not quite like that. The illustration shows its construction. The block is done away with, since it runs in a groove on the sprocket rim; the usual link does the pulling instead, bearing on the flanges. Another style of description is to say that the construction is reversed, the link being one piece and central, being converted into a block, a space being cut out so that it does not touch the sprocket in bending, while the usual block is doubled and runs on the flanges. The same quality of steel is used throughout, and the grain all runs lengthwise. Strength, great endurance and a reduction of a fourth in friction are claimed. Use must decide the degree of improvement, but the chain certainly runs smoothly and attractively.