CHAPTER IV.
THE DIRECT APPLICATION OF POWER.
It is evident that one of the greatest, if not the very greatest, of the requirements of a practical road wheel, or a man-motor carriage, is that the power of the rider shall be transmitted to the said wheel in the most direct manner possible; that is, by causing the strain to come upon the muscles in such a way that these muscles shall be placed in the best possible position to overcome such strain, and to take advantage of such conditions as nature has already provided for, in training our muscles to the work we have had to do under the oldrégime, without the wheel.
The muscles of man are best adapted to a direct pull or push. If we push upon a weight with the muscles at an angle to the direction in which we want the weight to move, the effective power is limited in the same way that the effect upon a weight is limited if we push at it in a direction at an angle to that in which we wish to move it; that is to say, not the total, but only a portion of the power will be effective in moving the weight.
The above facts apply particularly to our subject when we desire to transmit motion to a wheel by means of the weight or gravity of our bodies. Gravity acting downward in a vertical line, if we are not placed over the resistance, the resultant effect is in proportion to the cosine of the angle at which we work, as follows:
LetW= the weight of the man andabe the centre of gravity and also the location of the source of power of said weight, and letcrepresent the point at which it is desired to apply the power to turn the wheel.
Power angle.
Power angle.
Now, it is known that the weightW, acting by gravity in the directionab, may be taken as proportional to the length of the lineab, and the portion of the pressurePin the directionac, which will be effective to turn the wheel, may be taken as proportional to the length of the lineac; that is,PW=acab, orP=acabW, whereacabis evidently always less than unity. Now, if the anglebacis thirty degrees, andW= 150 pounds,Wtimesacabis 130 pounds. Or, by trigonometry, the weightW, acting in the directionab, by gravity as in working a cycle, will have a resultant in the directionacrepresenting the power acting to turn the wheel equal toWcosbac. If the anglebacis thirty degrees andW= 150 pounds, thenWcosbac= 130 pounds. Now, in order to still get one hundred and fifty pounds of force on the wheel, a pull on the handle-bars would have to be given sufficient to make up the lost twenty pounds, which the rider would get without any pull on the bars if placed directly over the work. This pull, while not fatiguing to the legs beyond the necessary requirement of power, is an entire loss of work in the arms, and must tell on the system. This is all an additional loss to that which ensues from the fact that nature has fitted us to stand upright and not to work in an angular position; our every-day experience in walking gives us practice in a direct vertical strain onthe muscles of the body, and we should make it a point to apply our force as nature intended, in so far as it is applicable to our wheel method. These conditions apply more or less to any form of locomotion, and particularly to the cycle.
From the foregoing remarks we are amply justified in drawing the conclusion that the resultant force available in the application of the physical power of man is in proportion to the cosine of the angle at which he exercises this force. We are well aware that many apparent variations will occur when so rigid a mathematical fact comes to be applied to the exercise of man’s energy in driving a bicycle; but all we care for is to lead the reader well up to the point by means of reasoning, which we hope will give at least a partial hypothesis for a conclusion well demonstrated by practical experience. We assert that when we consider the application of thegravityof the body to work on either a bicycle, or to other work of similar requirements, our mathematical demonstration is strictly true. It is justifiable, therefore, from a purely theoretical stand-point, to say that the rider of a bicycle wants to get directly over the work; let us see how our experience demonstrates this conclusion.
Take first the differences between a modern ordinary bicycle and the old velocipede, or “bone-shaker,” so called. The former is lighter and better made; but the one great difference is that the rider is more nearly over his work. It was this one advance which encouraged the development of other minor differences which had been roughly thought out before. In fact, the Patent Office shows that many of these improvements were on record, but there would have been little use for them if the rider had not worked himself up into a place where he could do something. Just who raised him up from a midway position between the two wheels, the saddle seventy-five degrees back of the vertical through the drive-wheel axle, as in the old bone-shaker,to nearly the top of the forward wheel, working at an angle of thirty degrees, as in some ordinaries, we will not attempt to say; but when he got there he has been willing, for a long time at least, to try to stay there, even at the expense of frequently goingdownon the other side, much to his annoyance, particularly as the general construction of the thing compelled him to go down the other end up, which end nature did not intend for terrestrial impact. It may as well be stated just here, however, that when our rider raised and moved his saddle forward he would have gone clear up to the vertical had it not been that it was absolutely impossible for him to stay there at all without hanging a heavy counter-balance somewhere in the neighborhood of the rear wheel, a scheme which, by the way, has been really recommended in modern cycle history.
One excuse for dwelling upon the foregoing dissertation is that many casual observers and some riders, strange as it may seem, assert that in the development of the modern rear-driving Rover pattern, we have been retrograding to the old velocipede, whereas, in fact, we have made another step forward of a similar nature to that spoken of before in raising the rider up above the point of application of power. In the Rover machine we have landed the rider practically where, as before said, he could not remain at all before; but in this new machine he has gained the advantage of being able to stay there.
Thus our rider has been gradually getting up and over the work. Various devices have been used in order to facilitate this operation, but, unfortunately for our power-development theory, many of the changes have been coupled with the safety feature so prominently that, in efforts by makers to place the rider in the best possible position for work, the safety feature is all that the casual observer has been able to see; therefore it is that in several machines, such as that called the “Extraordinary Challenge,” the sales havebeen made more on the strength of safety than on their other great point of real merit, the advantage in power. In such machines, the rider has often been surprised to find that he had more power than he supposed, but having bought his mount with a view to safety, and it being still found to contain almost as great an element of risk as he before incurred, considerable disfavor has been the result. Had the element of increased power been thoroughly understood and appreciated, such machines would, in spite of the great deterioration in appearance, have been regarded more kindly.
No better illustration in other arts of the desire and tendency of the operator to get over his work can be had than in that of the ordinary foot-lathe. No maker of lathes would think of attaching a treadle in such a manner that the workman could not perch himself directly over it. In some experiments on foot-lathes, the writer found that he could run at a given speed and resistance three times as long when over the work as when standing some twelve inches back and he had to reach out for it; in fact, it seems quite evident that our theoretical conclusion is fully established in actual practice.
Granting then that the direct vertical application of power by the rider is a desirable acquisition, let it be called a fundamental requirement. It must not, however, be supposed, in this connection, that the foregoing in any way justifies the swimming position, or kicking back, which some experimenters have of late been prone to adopt. We must approach but never get beyond the vertical limit.
Since this manuscript has been ready for the publisher, articles in theBicycling Newsby “Warrior” and “Semi-Racer” have come under my notice, from which I clip sections, appertaining to this subject, as follows:
“If, as ‘Crawler’ says, it is a very great improvement to have the saddle well over the pedals, how comes it that the contrary isnow so universally advised, and as much as four inches recommended between the line of saddle-peak and the line of crank-axle? There never was a greater mistake made than when the saddle was generally placed in advance of the crank-axle. Apart altogether from its effect on the steering or easy running of the machine, there are two very strong reasons why the saddle should be kept well back. In the first place, it is quite impossible to sit upon the tuberosities designed by nature to carry the weight of the body unless the legs are flexed at the hip-joints. The parts resting upon the saddle are, otherwise, soft and delicate structures, liable to injury from the violence of the saddle. Were it for no other reason, this is enough to determine the position well to the rear of the crank-axle. But another reason: it is not a fact that one has greater power with the saddle, as suggested by ‘Crawler.’ One may certainly throw hisweightalternately upon either pedal readier, because he is nearer a standing position; but, on the other hand, with the saddle well back and the handles well forward, the purchase so obtained gives far greater power from muscular contraction than the mere weight of the body gives, and, indeed, many more muscles are called into action when the saddle is kept back.—Warrior.”“With regard to gearing, I consider that the position of the rider has much to do with this also. A rider sitting well back can use his ankles much more effectively than one right over the pedals, and can consequently exert a driving force through a considerably greater part of the stroke, whereas the vertical rider depends chiefly upon the weight of his body during a comparatively short portion of the down stroke for propulsion, and upon the momentum of the machine to carry him over the dead centre. It will be found, therefore, that the rider using his ankles properly will be able to drive at least three inches higher with the same amount of force, and, at the same time, there is much more equable strain on the machine.—Semi-Racer.”
“If, as ‘Crawler’ says, it is a very great improvement to have the saddle well over the pedals, how comes it that the contrary isnow so universally advised, and as much as four inches recommended between the line of saddle-peak and the line of crank-axle? There never was a greater mistake made than when the saddle was generally placed in advance of the crank-axle. Apart altogether from its effect on the steering or easy running of the machine, there are two very strong reasons why the saddle should be kept well back. In the first place, it is quite impossible to sit upon the tuberosities designed by nature to carry the weight of the body unless the legs are flexed at the hip-joints. The parts resting upon the saddle are, otherwise, soft and delicate structures, liable to injury from the violence of the saddle. Were it for no other reason, this is enough to determine the position well to the rear of the crank-axle. But another reason: it is not a fact that one has greater power with the saddle, as suggested by ‘Crawler.’ One may certainly throw hisweightalternately upon either pedal readier, because he is nearer a standing position; but, on the other hand, with the saddle well back and the handles well forward, the purchase so obtained gives far greater power from muscular contraction than the mere weight of the body gives, and, indeed, many more muscles are called into action when the saddle is kept back.—Warrior.”
“With regard to gearing, I consider that the position of the rider has much to do with this also. A rider sitting well back can use his ankles much more effectively than one right over the pedals, and can consequently exert a driving force through a considerably greater part of the stroke, whereas the vertical rider depends chiefly upon the weight of his body during a comparatively short portion of the down stroke for propulsion, and upon the momentum of the machine to carry him over the dead centre. It will be found, therefore, that the rider using his ankles properly will be able to drive at least three inches higher with the same amount of force, and, at the same time, there is much more equable strain on the machine.—Semi-Racer.”
The quotations show one great trouble in writing a book: such a long time elapses between writing and publishing, that new facts and opinions come up in the mean time which demand attention and suggest alteration, as, for instance, my former paragraph in regard to the swimming attitude should have been expanded.
“Warrior” carries his theory to extremes. He is all right in cautiously avoiding an unduly-forward saddle, but when he places the front tip back of the vertical through the crank-axle, he goes too far and is utterly wrong.
The cause for such diversity of opinion in this matteris that it is tested under different circumstances. In riding over an easy, slightly rolling country, the tendency to get back on the saddle is indisputable, for reasons noted by “Warrior” and fully treated of in my chapter on “Saddles and Springs in Relation to Health;” but notice how we slip forward, almost off the saddle, when we have any work to do, as in mounting a difficult hill; and also notice that the farther forward we get, and the less the angle at the pedals between the saddle and the vertical, the less will be the pull on the handle-bar. (See early part of this chapter.)
In this connection the very long saddles, largely adopted in America, are of great advantage, since, when not working hard, the rider can sit well back and then slide forward when occasion demands. What “Warrior” means by “greater power from muscular contraction” is rather ambiguous. I may admit that more power can be consumed when the saddle is back, but I deny that more effective power to turn the wheel can be maintained. The rider may get more exercise from “muscular contraction” than from the effect of his weight, but he will cover less distance with equal fatigue.
As to “Semi-Racer,” his statement, that more ankle-motion is available when sitting back, is absurd. Will he not lose in “clawing” force below what he gains above?
In my chapter on “Ankle-Motion” I would say that the wonderful power therein asserted as possible was attained by having the saddle well over the work. Before disposing finally of this digression, let me express my pleasure that these subjects are meeting with general and enlightened discussion. However much opinions may differ, I regret, as a loyal Yankee, that we in America have to depend so largely upon cross-water importations for the initiative; but it is hoped that such importations may always be on the free list, maugre the high-tariff proclivities of the writer and many others like him on this side.
The next point of importance is the mechanical means whereby the rider transmits a revolving motion to the drive-wheel, and to lead up to this let us discuss the evolution from walking to riding. The actual development has been of a legitimate character; first, walking; second, walking with the trunk supported on rolling mechanism; third, propulsion by means of mechanical things like legs, the entire body supported upon rolling mechanism; fourth, propulsion and support all by means of, and upon, rolling mechanism.
The Dennis Johnson wheel.
The Dennis Johnson wheel.
The early bicycle, such as that of Dennis Johnson, patented in England, No. 4321, 1818, did not support the rider entirely free from the ground. It consisted in a pair of wheels placed under him, constituting a sort of third or rolling leg, the feet, though not for support, still touching the ground. This machine is a fair sample of an intermediate stage between the era of oscillating devices subjoined to the trunk by nature—to wit, the legs—and that of the present cycle. Inthe Johnson machine the legs are used for projectile force only, and serve as a motor, the weight of the body being supported on rolling mechanism as aforesaid; hence it was a more natural and palpable sequence to walking than other prior contrivances in which the rider was raised upon a platform such as shown in the machine of Bolton, patented in the United States, September 29, 1804.
The Bolton machine.
The Bolton machine.
The Bolton and similar machines really belong to a different class from that of Johnson, but if we confine ourselves to our bicycle or balancing-machine, thus throwing out the Bolton class, the development from the leg to the wheel method proceeded in order, for we have next the Lallement crank-wheel, United States patent, November 20, 1866, which represents substantially the present single-track type.
The Lallement machine.
The Lallement machine.
One illustrious gentleman, Croft by name, patented a machine in the United States, August 21, 1877.[4]
The Croft machine.
The Croft machine.
In the Croft machine a pair of bars held in the hands are used with which to propel by pushing against the ground, instead of using the legs as in the Johnson. By supporting the body entirely free from the roadway, Croft takes a step in advance of Johnson, but he still retains his propulsive power by means of oscillating devices having contact with the ground, and in this respect might be said to use a pair of mechanical legs. He combined a walking method with that of rolling, as was the case with Johnson and Baron Draise, but he seemed to think a mechanical extension to the arms a better medium through which to pass his energy than nature’s own devices for that purpose. Quite a number of inventors have gone astray on this question of the power of the arms in these manumotors. No doubt the arms could be made to help, but our present physical development suggests the legs as better; especially if one or the other plan is to be used alone. True, theCroft machine could use the entire body, as in the case of a man shoving a flat-boat or scow upon the water, but the inventor’s engraving does not show any such effort as necessary. What a pity that we did not have a single-track machine, propelled by the Croft process, between the time of Johnson and Lallement; how nicely it would have helped us out in our chronological development. We of the wheeling fraternity may, however, take a crumb of comfort from the fact that the two bicycles, or balancing machines, did make their appearance in respectful logical order.
In naming the Bolton, Johnson, Lallement, and Croft machines, I have not taken the trouble to ascertain whether they all were the very first machines of the kind in the art, nor would it matter whether they were or not, unless it could be shown that others were of equal prominence. We should not recognize mere vagaries as an advance in the art: the above gentlemen patented their machines, and it is therefore reasonable to suppose that they were real workers, and not simply chimerical characters flitting about in the minds of recent explorers. The famous Draisaine is worthy of mention, but our man Dennis will answer all purposes of illustration. Galvin Dalzell is now reputed to have been the first to raise himself from the ground on a single-track machine, and back as far as 1693 one Ozanam, a Frenchman, is said to have made a four-wheeled vehicle of the Bolton type, but driven by the legs.
Blanchard, about 1780, did some work in connection with the subject, and one Nicephore Niepse, we are told, made a machine of the Johnson type about the year 1815. For further information on this subject, see “Sewing-Machine and Cycle News,” inWheelman’s Gazette, September, 1888.
In quite a recent edition ofThe Wheelthe editor gives us a little foretaste of a book to which we look forward with interest. In it he mentions improvementsby Gompertz in 1821, Mareschal, Woirin, and Leconde as having worked on cranks in 1865, and David Santon as having brought a wheel to America in 1876.
L. F. A. Reviere, of England, is said to have made the large front and small rear wheel; C. K. Bradford, of America, the rubber tire; E. A. Gilman, of England, anti-friction bearings, and A. D. Chandler, of Boston, is mentioned as an importer and rider of 1877.
[4]This is not a misprint for 1777.
[4]This is not a misprint for 1777.