Compared to what supercars offer, a 200 horsepower superbike like the BMW S 1000 RR can seem almost quaint. Some new hot hatches produce more power, after all. But then, a motorcycle doesn’t need as much power as a car because it is so much lighter. For example, my 2012 $ 4,300 Street Triple R has about the same power-to-weight ratio as a multi-million dollar McLaren F1.
However, it is not always easy to compare motorcycle specifications such as horsepower and torque. Depending on the model, this may even be impossible for the average consumer. This is because not all manufacturers list all the horsepower and torque figures for their bikes. But why is that?
Measuring the horsepower and torque of a motorcycle is not as easy as it seems
First of all, it’s important to note that just because a company doesn’t list the horsepower and torque of a specific motorcycle that doesn’t mean it doesn’t know about them. After all, even in the United States, motorcycles must pass emissions tests. And like cars, that involves putting them on a dynamometer, aka a “dyno.” But dynos aren’t expressly designed for emissions testing – they’re also meant to measure performance.
As with specific cars, motorcycle dynos generally come in two forms. Enthusiasts are probably familiar with chassis dynos, which calculate horsepower and torque at the rear wheel, RideApart Explain. But manufacturers typically use engine dynos, which attach directly to the engine via the flywheel and crankshaft. The former are like conveyor belts that the motorbike turns. A computer then converts the measured force into torque and calculates horsepower from it and the engine speed. During this time, the latter runs the engine directly at a defined speed and calculates the torque and power from the power absorbed.
This is where the gap lies. Car and motorcycle manufacturers typically report crank horsepower and torque. The powertrain, however, absorbs some of that output, resulting in lower numbers for the rear wheels. But to be fair, the industry knows it. There is even a general estimate of 10-15% transmission loss on the car side.
However, this figure does not necessarily work for motorcycles. This is because, apart from electric vehicles, all cars rely on strong drive shafts to send power to their wheels. But bikes can have chain or belt drives instead, and they have different levels of loss. And that’s before we get into how gear ratios, axle ratios, and sprockets manipulate rear wheel torque values.
Additionally, dynamometer results are not always consistent for the same vehicle. Changes in ambient temperature, humidity, altitude, etc. may affect the results. And although the correction factors can take these variables into account, they are not always consistent from one dyno to another or from one company to another, RideApart Remarks.
The exact horsepower and torque of the motorcycle is neither required nor necessary in the United States
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However, even with this uncertainty, automakers routinely list horsepower and torque figures for their vehicles. So why isn’t this as common on the motorcycle side?
That’s not to say that motorcycle manufacturers don’t list official powers and torques here at all. For example, Harley-Davidson provides the double digits for the new Pan America and Sportster S. Indian does the same with the FTR. However, both brands only list the tightening torques for their other cruising bikes.
This apparent lack of information does not end there. Kawasaki, for example, doesn’t list the power of the Supercharged Ninja H2 on its website, only its torque output. And that doesn’t even say that for the smaller capacity Ninjas. Meanwhile, Suzuki has official numbers for the Hayabusa 2022, but they aren’t listed on its US website. On the other hand, Ducati freely displays the power and torque of all its motorcycles.
So why these discrepancies? Officially, there is no reason. But there are a few possibilities. On the one hand, businesses might be concerned about the potential for legal and / or insurance backlash. That’s why Japanese OEMs signed the gentleman’s agreement after the launch of the first Hayabusa, after all.
Focusing on cruisers, horsepower is usually not as important as torque, and maximizing the latter means sacrificing some of the former, Bike world Explain. So, it doesn’t matter that air-cooled V-twins don’t produce as much power as their liquid-cooled counterparts. Still, potential buyers might not appreciate seeing these lower numbers. It could also explain why small capacity sports bikes don’t give their horsepower and torque figures, but larger ones sometimes do.
But speculation aside, there is simply no law that requires motorcycle manufacturers to list the horsepower and torque of their bikes. So, unless the segment demands the information, there is no impetus to deliver it.
These specs matter much more to overseas racers, although
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At least that’s the case in the United States. But overseas, especially in Europe, things are different. And this concerns the different types of motorcycle license.
Here in the United States, once you’ve passed your test – or taken the MSF course – and obtained your license, you can ride the bike you want. Big, small, powerful, economical, it doesn’t matter. But this is not the case in the UK, Multichannel network Explain. For one thing, you need to be at least 17 years old, rather than 16 like in most US states. Second, the UK has Compulsory Basic Training Certificates (CBTs), rather than permits. And third, before you get a full license, you go through a few interim steps.
The first step after obtaining your CBT is the A1 motorcycle license, which limits you to 125cc motorcycles not exceeding 15 hp. And after your 19e anniversary, you can get an A2 license, which brings the power bar up to 47 horsepower. It was only after getting the full A license at age 21 that the UK lifted all motorcycle horsepower restrictions.
These licensing laws encourage motorcycle manufacturers to publish horsepower and torque ratings. After all, they have to make sure that they and potential buyers are playing by the rules. And since even small capacity models must have official numbers, it makes sense to release them for the rest of the range as well.
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