Written by Gunnar Skrydstrup
Reproduced with the permission of the M.C.T.C.
Two V-four Honda-models
VF 750 F and VF 750 S
When Honda launched the first motorbikes with a water-cooled V-four engine in 1984, not many expected that this type of engine would be the most used engine in Honda's range and that it almost would replace the four-cylinder in-line engine.
But that is a fact, and this year there will be four Honda models with V-four engines on the Danish market. Last summer we tested two of these models, the VF 750 F and the VF 750 S. Due to the fact that the engines are almost identical, we have chosen to bring the tests of the two bikes together even though the bikes all in all are very different. The S-model feels rather heavy and pretty sluggish in the steering and is most suitable for long straight ahead rides. The F-model is good for bends, easy to steer, and only suitable for solo rides.
The VF 750 F was just put on the market in 1983, but the VF 750 S was introduced abroad two years ago. The first year's version of the S-model was not exactly praised for its road-holding qualities and as a result Honda altered the 1983-model, which we test rode, by making some changes at the steering stem and giving the bike a slightly longer wheel base. At the same time the air injection system was made more efficient, and the power output was lifted from 78 to 86 hp at 9500 rmp.
Both the S-model and the F-model are constructed after the same principle with 90 degrees between the cylinders, four overhead camshafts, 16 valves, and a hydraulic clutch, but the F-model has four h.p. more than the S-model and for that reason only a few parts can be used in both engines.
In order to make the engine shorter and make it possible to shorten the wheel base, the front cylinder in the F-engine points upward in an angle of 45 degrees whereas the front cylinder is nearer the horizontal level in the S-engine. This alteration made it necessary to construct a whole new cylinder block for the F-model.
Both bikes have a distinctly refined engine, and the S-model has almost to be described as super refined. The VF 750 F goes silky smooth up to 5000 rpm, but then it starts to make minor vibrations which increases a bit from 6000 rpm. Compared to most other motorbikes the F-model has to be described as almost vibration less.
Both engines can pull clean in high gear from about 1500 rpm, if you handle the throttle hand lever controlled, but the action starts around 3000 rmp. Furthermore the VF 750 F test bike had some problems in the carburation about 250 revolutions on each side of 6000 rpm. Nevertheless its accelerating capacity from 60 kilometers per hour in the highest gears was absolutely first class. The same has to be said about the VF 750 S which has six gears and a higher total gearing in the top gears than the F-model.
Regarding the accelerating capacity through the gears the two bikes are also among the absolutely fastest in the 750 cc category. As to the top speed the VF 750 F is the fastest and the VF 750 F the second fastest 750 cubic-model, we have tested so far.
The S-model reached 60 kilometers per hour fastest in the acceleration test. That is due to the fact that the S-model's transmission system worked satisfactorily apart from the fact that the clutch was a bit harder to pull than usual for Japanese motorbikes.
The F-model's clutch grabbed on the other hand by quick starts which made it pretty difficult to keep the front part of the bike near the ground and consequently it costed some tenth seconds, which the bike however quickly caught up with.
We were for that matter not very impressed by the VF 750 F's transmission system in general. Firstly there was pretty much slug which was intensified by the fact that the engine reacted very sudden on gas changes. Secondly the change of gears did not work satisfactorily. The test bike's gearbox changed pretty well, when the engine was cold or thoroughly warm, but when it not was thoroughly warm after a couple of kilometers ride the change of gears could be so difficult that you only could change by a certain number of revolutions without really exerting yourself. And in these situations it was often necessary to use intermediate gas when gearing down.
Conversations with several foreign MC-journalists and intensive reading of foreign magazines have shown that the test bike's gear change not is alone with this problem, but on the other hand it is far from all the VF 750 F's gear changes which have this problem.
The S-model's gear change had a widespread tendency to make a noise by changes, but apart from that it worked both easily and exactly.
Compared to traditional European sports bikes, the VF 750 F is comfortable, but in this respect it was not a match for the VF 750 S. There is especially one point where the S-model is better than the F-model and this is regarding the passenger comfort. Or in other words, on the F-model there is absolutely nothing which resembles passenger comfort. At least not when it comes to persons from medium size and upwards.
The F-model's seat actually looks quite reasonable, and the front part is in fact acceptable for this type of bike. But at the back there is firstly not enough seat. Secondly you sit so high with your legs that you almost take the shape of a ball. Due to the fact that you do not get any counterweight from your legs, you are inclined to wobble when the rider steps on the brake or revs up the engine. It does not get any better by the fact that the two handles on the side of the seat are difficult to reach and to hold properly on to. In short the VF 750 F is not a bike for people, who often ride with pillion passengers.
The riding position for the rider of a VF 750 F is considerably better than that of a possible passenger.
However, the footrests in front also sit high and one of the test riders reported some tenderness under the soles of the feet after a ride across half Jutland. Another test rider observed that his arms got sore by slow riding, but luckily that can be managed. Besides, it was never Honda's intention that a VF 750 F should be used for slow riding.
However, during long and fast riding where the rider sits in a relatively upright position, the F-model has a weakness. In this case could the narrow screen at certain winds namely fling the air current so powerfully in the face of the rider that it gets a little unpleasant in the long run. If you lean forward, as it often is the case by sportive riding, the wind is directed over your head.
The riding position on the S-model is good and immediately more relaxed than on the F-model. But the "natural" speed in headwind is only about 120 kilometers per hour because of the pretty wide handlebars and the more upright riding position. Under more favorable winds you can keep a speed on about 150 kilometers per hour without any effort.
The VF 750 S has a wide seat with a padding, which is soft at the top and firmer at the bottom. After a couple of hours ride you can feel that you have been sitting on the seat, but you are not sore.
From a comfort point of view the S-model's front fork appears to be nearly perfect. It absorbs all kinds of bumps, so that you can hardly feel that they are there.
The rear end works fine too, most of the time, but it does not quite absorb medium-sized bumps and if bump follows bump the bike stamped with the rear wheel. As a whole the VF 750 S can by today's standards still be described as a comfortable motor bike.
The VF 750 F is not as comfortable as the S-model, but compared to several other sports bikes the comfort is almost deluxe. The front fork has difficulties absorbing the shocks when many soft bumps follow each other, but apart from that it absorbs fine even though it is adjusted comparatively hard for sportive riding. The same applies to the rear end.
The point where the two VF-models really differ is with regard to the road-holding qualities. The VF 750 F is very easy to steer, while the VF 750 S with its big caster and long wheel base seems somewhat slow and heavy in the steering in the first phase of a course change. At the same time it has a tendency to drop into bends by slow riding when the first sluggishness has gone.
The S-model does not immediately tempt to riding on winded roads. But it is possible to ride it pretty fast on twisty roads and even in long, quick bends with a somewhat bumpy, uneven rough road surface it is stable and feels safe. Only in a couple of cases we noticed small jerks in the handlebars. The ground clearance is fine. We had only the left footrest in the asphalt and it actually first happened when we deliberately provoked it.
Many Japanese bikes have problems with lengthwise roughness on the road, but the S-model does not react neither on white stripes nor on lengthwise patches. And no matter how fast you are riding straight ahead, the directorial stability is first class.
The F-model's directorial stability is also satisfactory even though it is unusual easy to swing.
Swings from side to side in S-curves happen almost automatically, and the bike can be swung very low without anything touches the asphalt.
The pleasure is increased further by the fact that the F-model steers neutrally and very precisely. All in all it gives a feeling of safety and authority, which only a very few bikes do, ex. the Honda CB 1100 R. The VF-model does not feel so exclusive and exceptional as the 1100 R-model, but on twisty roads it will in many situations probably show the 1100-model the way.
No matter whether the road is straight or twisting there is no other 750-model on the market which can compete with the VF 750 F-model. This is not to say that it is completely stable in rough bends if the bends are ridden through with high speed. But the minor vibrations which in some cases can be noticed when all caution is thrown overboard, arises in any case first at a rate of speed where most other motorcyclist already have given up. In these cases the F-model feels safe and you can without problems let the throttle hand lever be where it is.
The Honda VF 750 F is a bike which tempts to fast riding, so luckily the brakes are absolutely first class. The front brake is extremely efficient. It is also easy to handle, because it grabs even and powerfully as the lever is squeezed. The rear brake demands a very hard squeeze in order to lock. You avoid rear wheel locks when braking hard this way, and that is the way it should be on a sports bike.
The S-model's brakes is also first class, and its front disc brakes work very fine in rainy weather, too. The drum brake at the rear wheel manages its work well and does not leave any need for a disc.
Lumped together the rest of the VF-models' accessories are good too. However, the S-model's fuel tank is too small to efficient long-distance riding and its dip switch is also too small and too hard to switch. The F-model's switches got nothing but praise from the test riders.
The F-model's instruments are rather traditional and consist of an about 4% too optimistic speedometer and tachometer, water temperature gauge, fuel gauge, and various indicators.
The VF 750 Sī instruments are more unconventional and include a lot of electronically indicators. When the engine is started different signs show in turn on the little display. By this procedure you can check if all control systems are working. When the fuel level reaches a certain low level, if the stop- or headlight bulb burn out, or if anything is wrong with the battery, water temperature, or the oil feed a warning light on the instrument panel light up. During the riding you can see on the little display, which gear you are riding in if you have any doubt. On the instrument panel there are besides water temperature gauge, fuel gauge and a digital watch with stop watch function. Besides all that the S-model has an automatic flasher system and another system which makes a noise if any unauthorized person should try to steal the bike.
A comparison between the two 750cc VF-models is a good example of the fact that the often asked question which motorbike is the best one, not is possible to answer before you have answered the question: the best one for what?
There is no doubt about fact which one of the two models Touring Nyt's test riders would like to own.
But if you prefer to ride relaxed, if you prefer comfort to sport, and if you
often need to ride with a passenger, then the VF 750 F is not the answer to your
dreams, in that case you are better off with the VF750S.