Most of us will instantly recognize the zip of a manual motorcycle engine from a distance due to the loud noise that most motorcycles make. But why do electric motorcycles produce comparatively little to no noise?
Electric motorcycles are quieter because they don’t have a loud combustion engine, exhaust pipe, or many mechanical parts. Instead, they run on stored electrical energy and make a negligible amount of noise.
Let’s explore why manual motorcycles make so much noise, why electric motorcycles are so quiet, and whether they are safe.
Why are Motorcycles Loud?
Motorcycles are loud because of their open engine design, smaller exhaust pipes, and heavy mechanical parts that produce heavy torque. Sometimes, riders will modify their motorcycle’s exhaust system, which increases the noise it makes.
For some, the loud revving sound of a motorcycle’s engine is music to their ears, but for others, it may be a curse. However, even unmodified motorcycles are much louder than cars.
Some reasons why motorcycles are so loud include:
Motorcycle Engines are Exposed
Unlike car engines which are built in a semi-closed compartment, motorcycle engines are more exposed. So the lack of protective covering around the engine means nothing can dampen the engine sound.
On the other hand, car engines are covered by an aluminum or metal casing, which absorbs or reflects some noise.
Motorcycles Have Smaller Exhausts and Mufflers
While some cars produce the same level or even more noise than motorcycles, they are much quieter due to the mufflers and sound-dampening design of the exhaust system. The typical car exhaust system contains mufflers and is designed to absorb more sound, keeping the car quiet.
Motorcycles also have mufflers, and most motorcycle exhausts have a sound-dampening design. However, the smaller exhaust system and mufflers on motorcycles are limited in how much they can reduce the engine sound, which is why motorcycles are comparatively louder.
The problem isn’t with the exhaust itself; it‘s with the design limitations of motorcycles.
Aftermarket Modifications Make a Motorcycle Engine Louder
While motorcycles are already louder than most other vehicles, they aren’t loud enough for some motorcycle enthusiasts. After all, motorcycle enthusiasts love the unique sound that many high-end two-stroke motorcycle engines make.
While most Harley Davidson bikes and other premium motorcycle models automatically produce these sounds, many people will modify their motorcycles to get the same sound effect.
It has to sound like a Harley Davidson, even if it‘s not one!
Unfortunately, some aftermarket exhausts and sound-boosting systems can go overboard with the noise, which can become a problem for other motorists and the public in general.
Some Motorcycle Engines are Louder by Design
It’s no secret that faster motorcycles have engines that produce more torque, and the louder sound produced by the engine is a by-product of the quicker acceleration. Therefore, motorcycles with a higher engine CC rating usually have faster acceleration and make comparatively more noise.
Older motorcycles with classic two-stroke engines will also produce more noise because of the simple engine design and the lack of advanced muffler or exhaust pipe systems. The same goes for the V-twin engines of Harley Davidson and other motorcycle brands.
Are Electric Motorcycles Quieter Than Manuals?
Electric motorcycles are much quieter than manuals since they don’t have heavy engines, loud mechanical parts, or exhaust systems. As a result, electric motorcycles hardly produce any internal sound, apart from minor machinery sound and wheels moving.
Electric motorcycles run on batteries, and no engine system means a smooth and quiet ride.
Some reasons why electric motorcycles are so quiet include the following:
The Lack of an Engine System
The loud combustion engines on manual motorcycles are the main cause of the noise they produce. While the mechanical parts in these engines also produce noise, the main problem is the fumes produced during the combustion process. These fumes make a lot of noise when they pass through the motorcycle’s exhaust.
Electric motorcycles run on batteries, which produce no noise when transferring energy to the wheels, so they don’t make even a fraction of the sound produced by manuals.
No Vibrations from Mechanical Parts
Manual motorcycles need supporting parts such as the exhaust, chain, and other mechanical parts. While essential, these parts contribute to the noise produced by the motorcycle.
Electric motorcycles don’t have combustion engines and therefore don’t need many of these clunky mechanical parts, which is why they’re so quiet (and lightweight).
Are Quiet Motorcycles Dangerous?
While no one likes too-loud motorcycles, and laws restrict how much noise a motorcycle can make, a too-quiet motorcycle can be dangerous. This is according to some experts who claim that a motorcycle that doesn’t make any noise can be a problem for pedestrians.
However, electric motorcycles aren’t soundless and can be heard due to moving mechanical parts. Also, drivers and pedestrians don’t rely on hearing alone, and people with vision impairment would get driving licenses!
So, while quiet motorcycles are more difficult to hear, they aren‘t dangerous if everyone follows the road rules.