CHAPTER XIV.

THE MODERN ROVER, OR REAR-DRIVING SAFETY.

As machines of this general type bid fair to engage the attention of cyclists to a marked degree, it seems in place to give them more than a passing notice in the general discussion. It is fair to presume that more than one-half of all the machines sold in the immediate future will be more or less after this general pattern.

The introduction of the Rover has afforded us one of the most amusing incidents in cycling history. The writer of these pages happened to be in Coventry during the summer of ’85, and he had a fortuitous opportunity, fondly accepted, of inventing fun at the expense of the “Crocodile” and of joining in the general laugh at the (alleged) ridiculous attempt of a Coventry firm to “foist” (sic) this most extraordinary freak of cycling inventive genius, under a new name, upon the market.

In the fall of the same year a notable Washington agent, allured by the attractive notices of a great prize for a hundred-mile race, imported one of these self-same incongruous specimens into this country. After a few weeks of hilarious humor, followed by a sullen contempt for the thing, this Washingtonian shipped it to a great American manufacturer, who made sport over it for a year or two before we all began to scramble around and make ready to prove that each one of us individually “saw it all the time.” It has been a hard pull, however, and it is still uncertain on whom it did first begin to dawn that somebody had been guilty of colossal stupidity.

One thing the Rover accomplishes, previouslytouched upon, is the location of the rider as nearly over the work as he chooses to be; which has been the end and aim of all our efforts in that direction. Had this machine been offered to the public, in good shape, at the end of the old bone-shakerrégime, it is questionable if the Ordinary would ever have acquired the prominence it did. In early times, when learning to ride a tall machine was considered quite a feat of gymnastic exercise, such as only the young and sprightly could ever perform, many, who afterwards by force of circumstances did accomplish the feat, would never have tried it if there had been anything else, such as the present Safety, to learn upon. Every accident on the Ordinary would have told heavily against it in the market, and every severe casualty would have made a new Safety rider; as it was, however, there was only one of three things to do,—take to a three-track machine, stop riding, or try the old mount again. It is needless to say that, almost to a man, the last condition was accepted, and the result is that now we have a class of men who can handle an Ordinary with such dexterity that many of them conscientiously aver that there can be nothing safer. However, among those most devoted to it at the present time there are few, if any, of the close observers who would have stood sponsor for their favorite machine had the rear-driver made its appearance in its present form prior to the advent of the Ordinary. To say that the latter would ever have obtained a footing above the level of a fad or a curiosity, would be equal to denying that the Safety will now ever hold an enviable place among us.

In the minds of many the sprocket-wheels and chain stood much against the introduction of the rear-driver; true, many good tricycles were implanted firmly on the market with such devices for conveying power to its necessary locality, but there was always such a vast chasm lying between the single- and double-track machines that riders did not care to get down to minutedetails of differences. To an Ordinary rider the idea of sprocket-wheels was, and is yet, for that matter, an abomination, only second to that of being dropped down from his elevated position to the humble plane in which his fellow on the Safety is wont to revel; but nothing in the way of change in the cycle art is unbearable after we become accustomed to it.

No doubt the old Kangaroo, as bad a failure as it was, led us up to endure more complacently the rear-driver in respect to the sprocket-chain; yet in no type of machine could the subject have been brought to our notice in a worse form. The tricycles using a single chain did away with one of the great evils which appertain to this system as found in the Kangaroo, in which we have two chains working entirely independently. The evil of such an arrangement is easily seen: no old Kangaroo rider, or rider of any other double-chain device, is ignorant of the annoyance caused by reversing the slack in each at every half-revolution of the pedal. Keep the chains ever so tight, this slack will be felt as the pedal crosses the dead-centre line at the top and the bottom. In spite of all this, some reputable makers persist in constructing rear-drivers having the double chain, and as a matter of course justly fail to meet with much approval from the riders thereof.

A word in regard to the nature of sprocket-wheels and chain. It is perhaps not generally understood how important it is that they should be well made, with especial view to resist stretching and alteration of pitch, any tightening device, no matter how deftly made, being an inconsistency in mechanics. To be sure, the spreading of the wheel-centres cannot do much harm, and it saves some annoyance, but it does not cure the real evil, nor is it any better to take a link out; it is the length of each and every link that is wrong, and it can only be cured by either changing each link or by altering the sizes of the sprocket wheels.

Two gear-wheels cannot run properly together unless they are proportional in size to the number of teeth. Now, the stretching of a sprocket-chain alters the pitch in a manner similar to that of retaining the same number of teeth in each of two intermeshing wheels, and then altering the size of one. A sprocket-chain acts substantially as an idle wheel; when it stretches we have, as it were, this idle wheel made larger while the size of the others and the number of teeth in each remain the same. Increasing the distance between the centres does not affect the size of the wheels, and when a sprocket-chain stretches or becomes longer by wear the wheels should either be larger or else the number of teeth diminished. It is a general idea among mechanics that chain gearing is about the most undesirable of all means of transmitting power we have. This is perhaps an exaggeration, and I think the cycle art has proved it to be so; but the idea no doubt is fostered by this constant tendency of the chain to stretch, and when this stretch takes place a very considerable amount of friction must result. There is another annoyance felt by patrons of the small wheel: the chains being low down and well oiled, as they should be, especially if once they become stretched, have a superlative capacity for accumulating and holding dirt, causing a grinding second only to that of a finely-set quartz-crusher. This feature is not so much to be deplored if the dirt can be kept out of the chain-link bearings, since it is not the wear of the link against the tooth of the wheel, but that within the link, which makes it longer, alters the pitch, and causes great friction.

We shall, however, have to accept this chain arrangement for the present in Safeties, as it cannot be helped. Some ingenious inventor will no doubt ere long come to our assistance; but until then we can tolerate it with a good grace, since it is a necessary concomitant of so valuable an acquisition to our assortment of mounts.

There is apparently little difference in the construction of the crank Rover Safeties, yet there is more than a cursory glance would lead us to suspect. To begin with, there is quite a variation in the slant of the neck or front fork, many makers giving a considerable curve to the fork, thus throwing the neck much straighter up. Then we have the telescope head, where the front fork revolves inside the tubular front extension of the main frame; and lastly, the swing-joint or Stanley head.

No very startling difference in the durability of these two heads has as yet developed itself. The telescope is often hung in balls, which makes it work as freely as the Stanley, if not more so; it has also a little advantage in appearance; still, a large majority of the makers have adopted the Stanley, probably because it is a little cheaper and quite as efficient. There seems to be less disadvantage in the slant of the front fork than might have been expected. According to an old theory in the Ordinary, the more nearly vertical the head, the less “sensitive” the steering; but experience demonstrates that by practice all machines are so easily steered that the point is really not so vital.

The original Rover machine as put upon the market has everything combined to give it a full slant in the neck; that is to say, it has a large thirty-six-inch front wheel and no curve to the fork, while in other machines of the same general pattern a thirty-inch front wheel is used with considerable curve to the fork, which taken together make the neck almost vertical; riders, however, are equally satisfied with either style.

It will be well to notice here that though I speak of the curve of the fork in relation to steering, it really has necessarily nothing to do with it, since a perfectly straight fork could have a more vertical head bearing than one much curved.

The slant of the pivotal line is the important feature,and this may be varied in either by bending the fork or, in the Stanley, by setting back the lower bearing.

The four drawings below show necks of equal slant and considerable variation in the curve or shape of the forks.

Rear-driver front forks.

Any of the four patterns above work exactly the same in the hands of the rider.

So much for the manner of obtaining slant of the head or pivotal connection, as we shall call it; but asto the amount of this slant it is desirable to obtain much more can be said.

The great system of castering, so knowingly discussed by some expounders of cycling faith, has in it really something of substantial importance. It is asserted that if the machine is so constructed that the line of pivotal connection strikes the ground in front of the point of contact of the wheel (seeFig. 1), a castering element comes into play which will cause the machine to retain its forward course, and enables the rider to go “hands off.” Note that the linea bstrikes atcin front ofd.

Supposed caster. Real caster.

I have observed many rear-drivers, and cannot see that this makes much difference; the various kinds seem to be equally well ridden, with respect to easy steering, if only the riders happen to be thorough experts; of course all sorts of theories in regard to the action of the steering have been advanced.

I take it that there is only one truly tenable theory of castering; this when applied will obviate “sensitiveness” completely and under all circumstances; it is as follows: The pivotal connection must be such that the linea bstrikes in front of the point of support, as before spoken of, and it must also be so constructed and placed in such a position that no motion of the handle-barwill cause the machine to lower its centre of gravity. If by turning the handles any weight is lowered, you can depend upon it that the force of gravity, always tending to lower this weight, will inversely cause the handle-bar to turn. It will be noticed that when the machine stands upright the steering apparatus is not in a state of stable equilibrium; that is to say, the weight of the machine tends to shift the wheel, and it can hardly keep straight by means of such castering element as results simply from the line of the pivotal connection striking in front of the point of contact.

The necessary conditions are as follows (seeFig. 2): The pivotal linea bmust strike atcin front ofd, and the linea b cmust be vertical in order that no motion on its axis can lower any weight when the machine stands upright. Now, it follows from these conditions that the head must be vertical and no part of the pivotal line in the rear of a vertical through the centre of the wheel.[6]

The automatic steering devices do not work as successfully on a bicycle as on the leading wheel of a tricycle. There are two principal plans which have been in use; in one of which a spring forces the steering-bar into a position for running straight ahead; the other plan for the same purpose consists in a V slot and pin. In the latter the weight of the rider keeps the wheel straight by forcing the pin into the bottom of the V slot, and it will rest there until forced out by the action of the handle-bar. Either of the above devices is objectionable in a bicycle, because the constant working of the steering-bar for the purpose of balancing is so continuous, as compared with that of steering pure and simple, that any force tending to hold it in any one position will soon tire the arms and make riding more laborious.

A new form of the rear-driving Safety was shownin the season of 1887, invented by a German. I give herewith a cut of the same, citing what he claims.

The “Rothigiesser” principle.

“Can be ridden any distance and on any road without using the handle-bar. The new principle—pedals on the rear wheel and saddle on the front wheel—is just the reverse of the construction of the ordinary bicycle, and is the only true principle for a Safety; the fault of the common rear-driving Safeties being that both saddle and pedals are fixed on the rear wheel, so that the front wheel must be controlled by the arms of the rider.”

I have tried the principle, but could not get much out of it. If there is anything in it at all it would be quite valuable; but I am inclined to the opinion that the inventor relied rather too much on his theory and not enough on actual practice. Notice that the handle-bar, trunk of the body, arms, and saddle are all within one system, there being no power to steer except in the action between the trunk and feet, instead of between the arms and trunk, as in other machines.

A new machine has been favorably noticed of late which strikes me as a modification of the German’s principle, or rather as a combination of that with the old plan of steering. In this device there is some motion between the saddle and the handles, as of old, and in addition thereto we find a motion between the saddle and the pedals, which is intended possibly to combine all of the good elements. The cut explains itself.

The “Rothigiesser” modification.

But to return to our mutton. The important features which have compelled us to recognize with favor this most homely and awkward-looking machine—the modern rear-driving Safety—are, first, the safety element, and, secondly, the advantage of being more nearly over the work, these two features including many minor characteristics. Then there are a number of independent peculiarities which can hardly be said to necessarily belong to this type of machine, but which are still adopted in it, such, for instance, as gearing upand down, foot-rests for coasting, etc. Until recently there did not seem to be any great fault in the machine except its looks, but a controversy has arisen which is not only extremely important but is so far unsettled; I refer to the discussion of theside-slip, which, in showing the number of explanations that different observers will give for the same set of facts, has been not unmixed with an element of the humorous.

[6]Since the subject of a patent.

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