In addition to the more obvious items such as maximum power output, there is also a list of specifications for the motorcycle that you may be interested in. But how much can you read about the motorcycle characteristics from the spec sheet?
If it's a new motorcycle, you can check it out on a test drive, but if it's a used or out-of-print motorcycle, you can only guess from the specs list. It is not easy to imagine the specs of the motorcycle even if they are written in numbers.
Just like the engine specs, you can read the motorcycle's characteristics pretty accurately from the spec sheet.
WebiQ is here to bring you a little happiness and motorcycle knowledge.
I'm talking about the trick of deciphering what kind of motorcycle it is from the spec sheet. This time it's the motorcycle!
Following on from the engine section, here's the on-road motorcycle!
As I wrote in the engine section, even if you imagine a motorcycle from a spec table, you can't read much into a moped 1 class (~50cc) scooter or an off-road vehicle. As with the engine, there are basically no major differences between the motorcycles, and there are very few things that are unique to each model.
For scooters and off-road vehicles, it's easier to imagine what kind of motorcycle it is from the picture of the body than from the specification list. For example, the shape of the scooter's floor can only be determined from the image.
Almost useless body size
This is the item that is often written at the top of the specifications around the motorcycle. The overall length, width, and height of the vehicle represent the body size.
The figures don't lie, but the "where to from" apparently varies from company to company, so they are not very useful for cross-manufacturer comparisons.
The overall width may be between the rearview mirrors or between the handlebar ends, and the overall height may be the top of the screen or the rearview mirrors.
The rear-view mirror is particularly crooked, and because of this, naked models are sometimes extremely large in height, but in reality, they are almost unaffected.
If you are hesitating to buy a naked vehicle because of the large size of the vehicle you see in the specification list, it may be unfounded.
Only the overall length can be compared between companies because it refers from the tip of the front tire to the rear end of the rear tire, but even if you only compare the length, it's still.
Can you load the tranny straight up? Or, can I park it straight and not jump out of the garage? And so on, it's only a little bit useful for those situations. In fact, the steering wheel is often turned to the left or right to stop the motorcycle, so if you have 5cm more space, just turn the steering wheel to solve the problem.
The impression you get when you look at the motorcycle is far more useful than the numbers on the spec sheet, and it is unlikely that you will experience a difference of 10mm or 20mm on the spec sheet. "If it had been 20mm thinner, I could have gotten through! There are almost no situations like that. I wouldn't worry too much about it.
Shaft distance (wheelbase)
This is the distance between the front axle (front wheel axle) and the rear axle (rear wheel axle). Even if the overall length, measured by the front and rear ends of the tire, is the same, there will be a difference in the wheelbase if the tire size is different.
This number is useful there, and it can be used to judge the rough character of the motorcycle by comparing it with similar models.
Wheelbase is"Long for stability, short for athleticism. So, if you look at whether the length is longer or shorter than your rivals, you can get an idea of what direction they are going. You can get an idea of the direction. However, in the case of a chain-driven motorcycle, about 10mm can be moved by adjusting the chain tension, so there is no need to be too nervous. You wouldn't be able to feel a 10mm difference in wheelbase.
However, there are some rare vehicles that are extremely long or short. As you can imagine, a 100mm difference is proof of a distinctly different direction, so if it doesn't match your desired direction, it's best to stop. If it has a wheelbase that is extremely short compared to its rivals, but its main purpose is long touring, it is hard to be happy because the design aims and what it wants to do are not the same.
And it's not the numbers themselves that are important. How does it fare against the rival motorcycles you are comparing it to? For example, the Suzuki Hayabusa and Kawasaki ZX-14R are two of the most popular high-speed tourers, but they have the exact same wheelbase of 1480mm. This allows us to determine that we are aiming for roughly the same place. And the Honda VFR1200F, which is also a long tourer but with a slightly different character, has a wheelbase of 1545mm, 65mm longer than its rivals.
This makes us wonder if despite its rather sporty appearance, the VFR1200F is designed more for long tourers? You can read about it here. (Although it is not possible to compare simply because the engine form is parallel and V type)
Seat height is for reference only
The seat height is the standard for "footing", but to be frank, this number isn't very useful. The seat height is the value when the motorcycle is standing upright, so when you actually step over the seat, the seat height will drop dramatically and the catalog value will be completely different.
Moreover, the sheets are not all parallel to the ground, but the measurement positions are not published. Apparently, the center of the seat is where your buttocks ride during the ride, but it's the lowest position at the front end of the seat that's important when considering footing, so it's still not helpful.
Also, footing is very much affected by the shape of the seat, the way the side covers are raised, and where the steps are positioned when you put your feet down, so it's not just low catalog value does not mean peace of mind.
If the difference is extreme, such as between on-road and off-road vehicles, the difference can be used as a guide. However, even if the difference is about 50mm, there are many cases where factors other than the numerical value are too large and cancel each other out.
Supersports have almost no sinkage, but the front end of the seat is often extremely narrowed and the step is at the back so it doesn't interfere with the footing, so the footing is surprisingly good even if the seat is very high on the spec. However, because the seat is sloped, if you try to put your foot on the seat in a normal riding position, you may not be able to do so at all.
On the other hand, even if the seat height of naked type is lower than the spec, the side cover is raised and the step is located at the position where you put your foot down, so the footing may be worse than the numerical value.
It is a foreign motorcycle that is extremely bad, and the seat surface is often wide and flat whether it is assumed that there is a certain height to begin with, and there are many vehicles with extreme footing that is not just a thing.
Either way, it's too early to give up or be relieved by the seat height figures in the specification sheet. It's just for reference.
Vehicle weight
I think there are many people who are worried about causing it when they knock it down, or are concerned about it as a guide when they push and pull it in a parking lot.
Even if you don't, I'm sure there are many people who refer to confirm that it's "light" as a guide to performance. Not helpful at all.
I think it is rare that you have actually measured the weight of the motorcycle after it is delivered, but when you actually measure it, the weight is often completely different from the catalog value.
However, even this is a lot better than it used to be. In the past, "dry weight" was often used, but this was the weight without engine oil and battery fluid, not to mention gasoline (fork oil and damper oil were also removed to reduce the spec weight). It was not uncommon.
Nowadays, they are a bit more decent and don't drain the suspension oil, but that is mostly up to the manufacturer, and in the real world, most of them are heavier than the spec list. Don't be too happy or sad with the weight on the specs, and don't think too strictly about it.
It's the complete opposite of "how to read a motorcycle from a spec sheet", but the weight of the motorcycle you feel isThe newer the year, the lighter it feels. It is also a good idea to keep in mind that the weight of the vehicle will have a direct effect on pushing up a hill, but even if the vehicle weight is a little heavier, the latest models can be pushed more lightly. Thanks to advances in body design technology, the center of gravity of the vehicle has been improved, and even in the liter class, the motorcycle feels almost the same as a heavy 400cc motorcycle from a long time ago.
Also, although you can't read it at all from the specs table, American and other models where the handlebars are far away from the center of gravity are difficult to push and pull with the handlebars, and V-type engine vehicles tend to have a higher center of gravity, so they tend to be unsupported all at once when they get wobbly.
Minimum turning radius
A minimum turning radius that almost no one cares about. The only people who might care about this are those who are not confident in making U-turns and care about being able to turn small.
In fact, the minimum turning radius listed in the spec sheet is the turning radius with the motorcycle upright and the handlebars turned all the way down, so the situation is quite different than when you are actually pushing and pulling.
When turning while pushing, the vehicle should be leaning slightly to the passenger side (left side) to prevent it from falling. In this case, a left turn will result in a smaller radius than the spec, and a right turn will result in a larger radius. If you can make a U-turn with the steering wheel fully locked while riding, the body of the motorcycle will fall down considerably, so you can turn with a much smaller radius than the specs show.
But it's not the turning radius itself that we need to focus on here. Is it bigger or smaller than similar motorcycle models? This is because if the turning radius is unusually large compared to similar vehicles, possibly less steering angle.
When you are driving normally, the steering wheel angle is not a big problem, but when you make a right-angle turn to the left slowly to enter a parking lot, for example, a small steering wheel angle becomes a big problem. It's okay if it's just a "small hard turn", but if you try to make a normal turn, you may hit the handlebar stopper with all your might far before you expect. When this happens, it's the same as if the handlebars were fixed, so you can't keep your balance and you'll fall over.
Some vehicles that originally had upright forks may have been converted to inverted forks after minor changes, but the larger diameter forks may have reduced the turning angle and increased the minimum turning radius. Be careful if the final turning radius has suddenly increased due to minor changes.
There are many people who think "I can't crash so easily because the angle of turn has decreased", but there are some motorcycles in the world that can't turn the steering wheel as much as you think. The minimum turning radius figure is a reference to measure the degree of "amazingness" of the motorcycle.
Caster angle and amount of trail
This is very important. Since it is directly related to the handling, we can say that this is the most important part of the specs around the body.
However, most people focus only on the caster angle and are relatively indifferent to the amount of trail.
But by far the most important factor is the amount of trail. A one degree difference in caster angle does not make much difference. One degree of caster angle does not make a noticeable difference to straight-line stability when cruising on the motorway, nor does one degree of caster angle make a decisive difference to the quickness of the motorcycle when driving through mountain passes. You may notice a difference (but only a slight one) on special motorcycles of the same make and model where the caster angle can be changed, but don't think that a one degree difference in caster angle on a different make and model will make a difference to the handling.
Caster angle
Theoretically, the less caster angle (the more it stands), the quicker the handling.
In other words. Determines the speed at which the steering wheel moves left and right. You are generally correct if you think that If it's a sport type, the caster angle has a smaller value (standing), and if it's a tourer type, the value is larger (sleeping), so it's true that this is the direction.
However, it is unlikely for a layman like us to feel the difference between a 24-degree caster angle (extreme sports type is usually around here) and a 25-degree caster angle (sporty naked type is around here).
Of course, the caster angle is quicker. But you wouldn't compare and contrast an American and a Supersport while staring at a spec sheet, would you? How does it compare against similar rival motorcycle? That should be the decision.
If the caster angle differs by one degree, it should not be assumed that the motorcycle with the higher caster has quicker handling.
The front part of a motorcycle is a very complex interplay of many different elements.
Tire diameter, tire width, fork stiffness, caster angle, toerail amount, load, suspension stroke, initial sink rate, steering head height, etc. Of these, the caster angle accounts for a considerable amount of influence, but the caster angle is almost the same for similar genres.
The slightest difference in caster angle between the motorcycles is insignificant. It is not possible to judge the quality of handling by looking at the specification list. It's not as simple as "I can make a quick turn because the caster is standing". The fact that the caster angle is not 0 degrees, even though it is a sports motorcycle where quicker should be better, is the result of a good balance of complex factors.
In addition, there is often a story like "......" that "the fork is contracted under braking to make the caster angle stand up for a quick initial turn", but unless you are a professional racer, you cannot experience such a thing. I assure you, that thing is just mistaking the various changes caused by shifting the weight to the front under braking as pulling out a quick initial turn. The factors other than the caster angle change are too great.
It is true that the characteristics change with the caster angle. It is also true that the more standing caster angle (less value), the quicker it moves. It is also true that the sleepier the caster angle (the higher the number), the better the linear stability. But rival motorcycles should have roughly similar caster angles, so don't worry too much about it. Here's a quick summary.
Trail amount
Theoretically, the greater the amount of trail, the better the handling in terms of straight-line stability. The trail is the distance between the point where the caster angle is set in the steering head and the point where the tyre actually touches the ground (i.e. just below the front axle).
It's hard to imagine, because the front tyre is at the very front of the motorcycle, but the front tyre is the point where the line stretched to the ground at the caster angle touches the fulcrum and the actual point of contact is pulled. The front tyre is pulled even though it is the furthest forward, which can be seen at. In other words, the amount of trail is a measure of 'how hard is it being pulled? In other words, the amount of trail is a measure of the amount of force being pulled.
Whereas the caster angle is a factor in determining 'how fast the handlebar is going to turn', the caster angle is a factor in determining 'how hard the handlebar is going to turn'. It's not the only factor.
However, the amount of trail is not the only important factor. If you're just going straight, the amount of trail is just a number that shows the stability of the motorcycle going straight. The amount of trail is very much affected by the leaning of the vehicle.
What does this mean?
By the caster angle, the ground contact point from the steering head to the ground is always in the centre of the motorcycle, but the ground contact point of the tyre moves to the side of the tyre as the motorcycle is banked. The greater the bank angle and the larger the tyre, the greater the amount of displacement.
This lateral displacement of the tyre and the extension of the caster angle causes the front tyre to slash left and right as it tries to return to a straight line. It's a bit complicated in words and even more complicated in diagrams, but try to imagine it in your mind.
The greater the amount of trail, the more the steering wheel will cut in an attempt to return to a straight line during banking. This makes a huge difference at low speeds, such as at junctions, where the steering angle is high and the banking is moderate.
The greater the amount of trail, the greater the angle of turn you can steer and the more responsive the steering wheel will feel. On the other hand, if the amount of trail is low, the handlebars will not turn as much during self-steer, making it easier for the rider to actively control the handlebars, but also reducing the feeling of security.
This difference is far more significant than the difference in caster angle. I have said that the difference in caster angle is almost imperceptible, but anyone can easily feel a difference of 5mm in the amount of trail, and a difference of 10mm is a big deal.
So the difference in the amount of trail can make a big difference to the character of the motorcycle.
More trail = more stability, more self-steer.
Less trail = more mobility, less self-steer.
Basically, this is how it works.
However, as mentioned in the section on caster angle, the front end of a motorcycle is made up of a complex mix of factors. It is not possible to judge the handling of a motorcycle by the amount of trail alone.
Combine and imagine.
For example, let's say you have a vehicle with a high trail volume, high caster, short wheelbase, light dry weight, and high seat height.
From what I can imagine, it's a self-steering, sport-oriented motorcycle, but it's so light that when there's a gap in the banking, it's almost like it's going to jump lightly, which can be quite scary because you have to steer the handlebars quickly and heavily. But if you use it well, you can go very fast, and the high seat height is for active control of the center of gravity, and the usual touring is on the road where the road is not rough, so it will be fine, but what do you think? You can think of it like this.
It's the lightest motorcycle on the market, with a high caster angle and a short wheelbase, so it's quick to handle and fast! But sometimes things don't work out as you imagined.
But things don't always work out the way you imagine. A motorcycle is an interconnected vehicle, and there are many things that are important that aren't mentioned in the spec sheet. For example, there is no mention of the very important center of gravity. So you can imagine what the motorcycle will be like from the spec sheet, but you can never be sure if it will be as you imagine.
It's interesting to imagine all these uncertainties, and when you test drive or take delivery of the motorcycle, you can enjoy the gap between your imagination and what you imagined, and try to find out why it was different from what you expected.