BEST FOOT FORWARD
(c) TONY FOALE. 1986 -- 1997
Enthusiasm can be a great thing. It can accomplish tasks otherwise impossible and can give tremendous personal satisfaction. But like many other good things, too much of it may generate problems, tunnel vision and complete intolerance to the views and needs of others being typical. In motorcycling, nowhere is this more pronounced than when the subject of feet first bikes is raised. Enthusiasm, either FOR or AGAINST, tends to be of the extreme variety. The detractors seem to feel threatened, and take up a defensive stance, refusing to even consider any possible merits. It is as if they fear that all their long held beliefs are being challenged and this makes them feel very insecure. On the other hand, the FF. lobby sometimes go overboard in support of their vehicles, often claiming benefits from features of dubious value, and often knocking characteristics of normal bikes which are by no means a problem.
I have had it in mind for a while to do an article taking an impassive look at the merits and demerits of this vehicle type. Firstly, perhaps I should declare whether I am in the pro. or anti. camp so that you can judge my remarks accordingly. Well, I am at the moment a true fence sitter, waiting to be convinced either way. When I first saw pictures of Malcolm Newell's startling Quasar, I reacted with the stock response of "that's no motorcycle, it's a two wheeled car", and promptly dismissed it. But as time went on I gradually warmed to the concept, and anyway, does it even matter if it is a single track car, as long as it does the biz. I am anxious to ride some of these machines so that I can check out their value personally.
To date I have only managed two and a bit rides. One was on Paul Blezard's Flying Banana, originally built by hub-centre specialist Jack Difazio for Royce Creasey. I don't think Paul would mind if I said that the bike was in need of some detail mechanical preparation, at the time of my ride. Unnoticed until after my test, the front brake hose was stretched like a guitar string, putting continuous tension on the steering. So it was hardly surprising that the general feel of the device did not fill me with sufficient confidence to throw it around with gay abandon. However, I tried to see beyond these defects and not be put off by things that had nothing to do with the FF. concept. Contrary to the findings of some other testers, I found no difficulty in starting from rest and moving off smoothly, and there seemed no problem with keeping balance. The degree of protection from the wind was also impressive. Those were really the only fair conclusions that I could form from that machine. To have condemned the genre for preparation faults that would render any bike uninspiring ( just plain dangerous ), would be unrealistic.
The second FF. that I've ridden was the "White Elephant". This machine is a stable mate of the previous one, having also been constructed by Mr. Difazio and also having a Honda CX. engine. This device was in much better condition, and I found it quite easy to ride. However, the steering seemed somewhat ponderous and I was of the opinion, whilst riding it, that the front tyre was too wide, later comfirmed when I returned and studied the front end. I think it fair to say that, most of the characteristics that I did not like could be blamed on that tyre. Another inconclusive test, I was left unconvinced but still opened minded.
I was then offered a go on a Quasar and jumped at the chance. However, it was as if fate was conspiring to prevent me from ever assessing properly the FF. phenomenon. This particular machine had its steering head bearings very badly out of adjustment, later confirmed to be about a massive 1/2 inch up and down movement, and this resulted in a bad tendency to wobble even at walking pace. Having an intense dislike of any bike that wobbles I was unwilling to proceed further, despite Paul Blezard's assertions that it improved with speed. Compared with the other two I found this machine very hard to balance whilst stationary, this was due to a combination of its massive weight and the angle that one's leg makes when supporting it. In a very short space of time I got severe cramp in my obviously under-used thigh muscles, which was ultimately responsible for my dropping the machine into the middle of the road in full view of it's owner. The strained muscles that I suffered, made it difficult to walk normally for the next two days.
Now you can understand what I meant by two and a bit test rides. But even though I am not in a position to give an objective rider's view point ( although I found nothing to say against the concept in general ), we can at least try to evaluate the things from a theoretical stance. The credit (or blame, depending on your point of view) for the current interest in this mode of fun making, should without doubt go to Malcolm Newell and his Quasar and more recently the Phasar, with more than a little help from Royce Creasey and latterly Paul Blezard. Even so it must be remembered that the concept is far from new. In the twenties or thereabouts there was the Ner-a-Car, and then in the fifties there were the very successful record breakers from NSU which took many speed records in the 50cc. to 250cc. classes. More recently there have of course been the American originated choppers and the like. Compared to conventional bikes the resiting of the rider into a telly watching position has three main physical effects on the machine.
Firstly, the frontal area will almost certainly be reduced and even without a fairing the drag coeffient ( Cd. ) may also be lowered due to an improved aerodynamic shape. Thus giving a double bonus in terms of drag, especially if advantage is taken of the improved fairing possibilities. In contrast the rider on a normal bike acts a bit like a horizontal parachute.
Secondly, the wheelbase is often longer than the accepted norms.
Thirdly, the combined C of G. of rider and machine is usually lowered. Mainly by lowering the rider but often also by lowering the weight of some dirty bits.
Let's see how these changes affect various aspects of performance.
The improved aerodynamics will obviously reduce power requirements to travel at a given speed and will reduce fuel consumption accordingly. The low long nature of these machines allow for the design of vastly more efficient body work to fully exploit the potential, as has been amply demonstrated by the NSUs. For directional stability it is desirable to have the sideways centre of pressure behind the C of G. and fortunately the FF. layout usually lends itself to this more than the latest race replica. The lower height and reduced drag also mean that aerodynamic lift over the front wheel is reduced without the need for drag increasing down force features. The sideways centre of pressure is also lower and this reduces the toppling over moment from side winds.
Longer wheelbase, this increases both the pitch and yaw moments of inertia. Putting it another way, it needs more effort to disturb it's attitude. This leads to a more stable and comfortable machine, and one that is less reluctant to suddenly slide. Disadvantages include slower handling and a greater turning circle. In most cases a longer bike is a heavier one, simply because more material is needed to connect the wheels together.
The lower centre of gravity is mainly beneficial but does have some disadvantages. Advantages include quicker and easier handling, and less weight transfer under braking. This can lead to improved braking because of the better balanced loads on the tyres. Let's look at some numbers to get a feel for the effects. ---- Imagine a hypothetical machine, with a 60" wheelbase and a 30" C of G height, and a 50/50 weight bias under static conditions. Then under the action of severe braking, say 1G., all the load on the rear wheel will be transferred to the front, and so the front tyre will be required to bear the total stopping forces. A machine under these circumstances will also be directionally unstable and only the skill of the rider can prevent the inevitable. Now consider a long, low rear engined FF. with a 85" wheelbase and an 18" C of G. height. Then under the same degree of braking only 42% of the previous weight transfer will take place. Resulting in improved braking and control. A beneficial side effect is that the tendency to dive is reduced.
Initiating a turn is usually a combination of some bodily weight movement and a bit of counter steering. The more secure riding position of an FF. largely eliminates the possibility of shifting the rider's weight and so all of the control function must come through steering input, but I don't see this as a problem, for normal riding, just a slightly different technique. In any case a lower C of G. means that less effort is needed anyway to provide the roll or leaning movements (i.e. we have a lower roll moment-of-inertia). Thus we get a quicker handling machine, which may well more than compensate for the opposite effect from the longer wheelbase. It is in side winds that a disadvantage of a low C of G. may be felt. Under the action of a steady breeze the machine must lean into the wind more, in order to balance the wind force. Of course with the FF. layout the lower mounted, body side area may well compensate for this effect. But the side area may well be greater anyway due to increased length and so negate this benefit. With gusty winds I expect that the FF. will be at a disadvantage. Any lowering of the sideways centre of pressure will probably be approximately proportional to the lowering of the C of G., whereas the roll moment-of-inertia will vary approximately as the square of the C of G. height. In other words the bike's resistance to the wind gusts will be decreased more than the disturbing effects from them. This means that the machine will experience greater roll angle changes, and as we have seen in earlier articles, roll movements cause steering movements through gyroscopic effects, thus aggravating the situation. Under some riding conditions I see the low rider C of G. giving problems of control. Apart from the wind case just described, I think a low machine C of G. is always desirable, but there are conditions where a high rider C of G. is very useful. Trials riders don't stand on their footrests just for the view. They do it because with a high body C of G. they can exert a greater influence over their steed, with a bit of "body English", as the Yanks call it. With the FF. not only is the rider's C of G. lower but he is largely prevented from moving about anyway.
Other features are sometimes claimed for these vehicles, but do not always stand up to scrutiny. So let's just look at a couple;
SAFETY ...This is often divided into two parts for convenience, viz;- primary safety, which is about avoiding the accident and secondary, which is about surviving it. A very important aspect of primary safety is the ability to see and be seen and under some conditions I see the FF. lacking in this regard. The low sight line of the rider will reduce his advance warning of trouble ahead and also make it more difficult to anticipate which way the road goes on a winding section. Anyone who has driven both low sports cars and high vans will know what I mean. In addition, the lower frontal area of these machines will not increase their visibility to the "sorry mate I didn't see you there" types. The 'pro' brigade claim that they have more control over their machines and are hence able to avoid some accident situations. If this is true, then all to the good. But theorising alone will not answer this question, this needs practical riding experience and I don't have that, yet. Also claimed is that secondary safety is improved because of the seating position and the simple supposition that it is better to smash one's legs than one's head. Published crashing advice suggests that the rider should tuck his arms in and hold tight, and let the bike take the knocks. This may be OK. for some prangs, but anyone who has seen film of dummies flying uncontrolled through the air, unrestained by seat belts in a crashing car, may be excused for thinking that this advice is easier said than done when it comes to a severe shunt. Motorcycles generally fall over, even in a very minor accident and often the ability to fall clear of the machine is quite useful. This is made more difficult with the FF. and the prospect of sliding down the road being dragged along by several hundred-weight of dead metal is not one that I relish. I find it difficult to accept that the current breed of FFs. are inherently safer than conventional machines, but I think that the basic layout lends itself to being potentially very good. To exploit this potential I think that the occupant/s needs to be encased in a very strong protective cell with energy absorbing crushable extremities. But even this would not be much use unless they were securely held in place with full harness seat belts.
COMFORT ...The general seating position should be more relaxing and less tiring on a long journey. The seat back can extend upward to support the whole upper body of the rider whose arms are then only required to support their own weight. One's arms will then suffer less fatique, and it seems reasonable to assume that they remain more capable of performing the various control functions. Even with an unfaired machine the rider will be better placed to withstand the constant wind battering which is such a feature of normal bikes. As mentioned before, the increased length slows the pitch response and this will give the rider a smoother ride.
Some years back stylist William Towns proposed an inter-city commuting vehicle. This was virtually a single track mid-engined sports car. A BMW boxer engine was to be mounted ahead of the rear wheel and just behind the rider, who lay/sat in a very low position with his feet ending up just behind the front wheel. This layout gives rise to a very long wheelbase, 100 inches in this case for just a single occupant, this length can be shortened if the front wheel is mounted between the legs. Malcolm Newell has done this on his recently constructed Kawasaki powered weapon. The wheel base in this case is down to 88 inches, but I expect that 'U' turns may still present problems. Towns (better known for his car styling and the Hustler kit car than for bike design, although he has been involved with Nortons), foresaw this problem and suggested a novel stabiliser wheel system which incorporated a small electric motor drive to give a reversing capability. This machine of his was to be totally enclosed with sliding doors for access. The car like interior would feature heating and the latest ICE. True comfort indeed! ---- Maybe not a bike in the true sense and perhaps a bit too efficient and clinical to be much fun, but as a way of packing in a lot of motorway miles in a day, and remaining relatively fresh, it could have a lot going for it.
The above advantages and disadvantages of FFs. translate into suitability or otherwise for specific types of use. --- eg. the low frontal area and efficient body shape undoubtibly make it very suitable for attempting speed records. Properly developed, I see this concept as being very useful also for racing. Particularly in the smaller classes where air drag eats away at the available power. If the FIM. could be persuaded to revise (better still, eliminate) their out dated, 1957, streamlining rules then the scope would be much greater. After-all knowledge of vehicle aerodynamics has improved somewhat in the last 29 years. In the larger classes the reduced weight transfer may create some problems with getting the power on to the road. Normally under acceleration, traction is improved by the increased load on the rear. Perhaps the machines would need to be built with a large rearward weight bias as with F1. cars. This would lead to stability problems, although these have been solved with the cars there is no guarantee that the same is possible with bikes. For long distance touring use I can see that the comfort and economy offered would be definite plus points. For lane scratching fun riding, I think that individual preferences would be the most important factor. Regardless of the merits of any alternative if you happen to like sitting on top of a conventional bicycle rather than sitting down, then keep doing it.
For serious off road use, the extra controllability derieved from the rider standing and throwing his weight about, as on a normal device, is too valuable to lose. I would be very surprised if the FF. form has anything to offer in the sports of trials, enduros or moto-X. The converted proclaim the FF. as not being a motor cycle, rather an advanced concept single track vehicle. I'm afraid that I see them as no more than a bike with a revised seating position, that brings with it various pros and cons.
That's it then, you pays your money and makes your choice. If the idea of taking your biking sitting down, appeals to you, then go for it. Don't despair if you have no wish to indulge because at least for the forseeable future it will still be much easier to buy a powered bicycle. As for me, I still remain open minded and when I get some time I want to modify one of my QLs. by resiting the fuel tank, footrests and controls. It can be done, I've checked. This will give me a known base from which to compare the two styles.
(2002 note) For me the situation hasn't changed. I have still not had the chance to ride a nicely built/prepared machine and as I haven't done any physical building for the last nine years, I haven't built one myself. However, my interest in building bikes has been rekindled of late and I'm considering a suitable project to work on. At the moment an FF with hydrostatic drive and an NSU style body is on the short list.