Cars are noticeably quieter today than even thirty years ago. I’m not sure why, maybe the computer controlling the engine and/or smog controls? It’s my understanding that most cities have ordinances and fines for glasspacks and other loud mufflers. I very rarely hear the throaty roar of a muscle car anymore.
Motorcycles haven’t changed. They still wake me up at 1AM when some jerk goes tearing out of our neighborhood. But even idling in traffic they are so loud compared to cars all around them. Their engines are so much smaller compared to a car but are so noisy. I realize teen riders love that roar, (I did too at that age) but not so much as an adult.
Why can’t companies make and sell quieter motorcycles?
They do. But the buyers then swap out or remove the stock mufflers.
Personally, I think there should be a concerted effort by police to start handing out tickets to every motorcycle that goes by with loud pipes. As it is, there appears to be no enforcement whatsoever.
Not all the noise comes from the exhaust. If you lift the bonnet (hood) of a modern car, you will see loads of sound insulation and padding in there. Motorcycle engines don’t have this.
Police here used to use water cooled motorcycles which, compared to their air cooled equivalent were near silent. I don’t know why they stopped using them.
Pretty much the same reason why lawn mowers are loud: exposed engines, the high cost of making them quiet (relative to the purchase price), and no regulations requiring them to be quieter.
In my neighborhood, the loud lawn mowers (including the one I use) are the biggest noise issue.
the owner swapped in a louder exhaust. Motorcycles (from the factory) have to meet the same drive-by noise regulations as cars. Even Harleys come from the factory with quiet mufflers.
as the guy above me said, motorcycles have their noisy mechanical bits all out there in the open, while cars bury them underhood/underneath with sound insulation.
More maintenance for a liquid cooled engine. Police bikes can have a lot of hours put on them and the cheaper to use the better. Also, a lot of departments in the U.S. want to use American made motorcycles, and until very recently all Harleys were air cooled. As were many foreign bikes that had squad packages. Police can’t use a liquid cooled bike if one that fits their uses isn’t being made.
But it’s true. A Harley direct from the factory is shockingly quiet compared to what you normally hear out on the street. Notice I say direct from the factory not direct from the dealer. Lots of dealers put different pipes on even before any customer orders them. If you heard a Harley with stock pipes on it you’d be amazed!
Negative. Even with the hood open a car still has the insulation and sound baffles that a motorcycle engine cannot have due to space restrictions.
cars are louder with the hood open. but car engines tend to have greater numbers of cylinders and run more smoothly than a bike engine (especially V-twins.) But some motorcycles still use straight-cut gears in the transmission (and valvetrain) and straight cut gears are noisy compared to helical spur gears.
I didn’t claim there weren’t, I just said I was dubious. My reasoning comes from a tv special I watched on Harleys. There was quite a bit made of their patented “sound”.
when a biker revs his engine, that deafening sound is definitely not straight cut gears.
they didn’t “patent” anything, they tried (and failed) to trademark their sound, which was challenged by the Japanese bike manufacturers who also made V-twin cruisers. And it wasn’t so much the “loudness” of the sound, but the particular firing cadence of their 45-degree V-twin with a single crankpin.
you’ve already been told that’s because those bikes have been altered by the owner/dealer to have a louder muffler or straight pipes. they don’t come that way from the factory.
I mean, it’s like cars. A lot of V8 Mustangs have aftermarket exhausts on them (I had Flowmasters on mine.) That doesn’t mean Mustangs are inherently louder than other cars. Once the owner starts modifying the vehicle, all bets are off.
I know quite a few bike riders. Most prefer a loud exhaust, they say it’s safer for them to be heard because they are not always seen. Also, unlike cars, motorcycles currently do not have the level of emissions requirements of cars and trucks. Swapping out the muffler for straight pipes can also add a bit of performance to a bike at a relatively low cost.
they’re getting pretty close, though. my Dyna has fuel injection complete with O2 sensors and a catalytic converter. it does not have a post-cat O2 sensor, so I don’t think bikes are (yet) bound to OBD-II.
Also of course many buyers prefer a loud motorcycle so there isn’t much market pressure to make them quieter.
There is some basis to the “loud pipes save lives” idea.
Well maybe not loud pipes, but certainly on a vehicle much faster than a bicycle, but not much easier to see, it helps to make some noise.
That’s not to make excuses for the jerks thundering round in the middle of the night.
Yes I was told and didn’t respond negatively to it. I was merely refuting your suggestion that the loud noise from bikes is caused by the gears which is nonsense.
I fully understand that many bike riders like loud bikes and will install pipes to increase the sound.
To answer the OP: Because some motorcyclists want to piss you off. Street motorcycles as they come from the factory are quiet. Loud ones have been deliberately modified to be loud.
Motorcycles do not have to be as loud as they are. Without larger more expensive exhausts they’ll be a little louder than cars because there’s no place like the bottom of a car to conceal them but they just need more baffling and insulation to decrease the sound. That’s it. They are louder because that makes them cooler, and often louder than they were built at the factory because the exhaust has been modified to make them louder using some pretense like it being safer or increasing engine efficiency by .00001%.
We’ve been over this in previous threads, it’s not going to change.
