A Quieter Motorcycle

[Kev m]

I found the EPA 1976/77 analysis on motorcycle noise emissions (published in final form in 1980) and reviewed parts of it (~400 pages of small type). An amazing study testing hundreds of motorcycles and multiple examples of each model tested. At the time they found the Honda GL1000 to be the quietest. (~78dBA).  In general they found that water cooled, shaft drives, and multiple smaller cylinders vs. 2 larger cylinders resulted in quieter motorcycles.  Based on this analysis they established the current 80 dBA noise standard so while some motorcycles may be quieter than that they are only required to certify that they meet the 80 dBA standard. Though my impression was that the BMW airheads were so quiet that was not matched by their data and they noted that BMW and Moto Guzzi and Harley Davidson would have trouble meeting a lower than 80 dBA level because of their larger and exposed cylinder configuration (in their analysis the BMWS were in the 80-82 dBA range). Of course this is all old data now but looks like I'll be happy with what I've got, though I would really like to stand on the street and listen to a V7II drive by. If I  had any friends who could drive a motorcycle I would do that. But I don't so I won't. I was standing near the street one day when a Suzuki TU250X drove by (same as my other motorcycle) and I was pleasantly amazed at how quiet it was.  Hearing it drive by sounded much different than sitting/riding on it.

Actually that gives me an idea.

Forget swapping mufflers. Download a decibel meter app and lets make some tests. Drive by a friend monitoring at a measured distance and at the rpm for "normal" operation (which will vary slightly by model).

But start with your V7II and how YOU like to ride it and take the base measurement then people with airheads could perform the same test and report back.

[Bonafide Bob]

I found the EPA 1976/77 analysis on motorcycle noise emissions (published in final form in 1980) and reviewed parts of it (~400 pages of small type). An amazing study testing hundreds of motorcycles and multiple examples of each model tested. At the time they found the Honda GL1000 to be the quietest. (~78dBA).  In general they found that water cooled, shaft drives, and multiple smaller cylinders vs. 2 larger cylinders resulted in quieter motorcycles.  Based on this analysis they established the current 80 dBA noise standard so while some motorcycles may be quieter than that they are only required to certify that they meet the 80 dBA standard. Though my impression was that the BMW airheads were so quiet that was not matched by their data and they noted that BMW and Moto Guzzi and Harley Davidson would have trouble meeting a lower than 80 dBA level because of their larger and exposed cylinder configuration (in their analysis the BMWS were in the 80-82 dBA range). Of course this is all old data now but looks like I'll be happy with what I've got, though I would really like to stand on the street and listen to a V7II drive by. If I  had any friends who could drive a motorcycle I would do that. But I don't so I won't. I was standing near the street one day when a Suzuki TU250X drove by (same as my other motorcycle) and I was pleasantly amazed at how quiet it was.  Hearing it drive by sounded much different than sitting/riding on it.

I have a 1977 R100/7 if you want to compare the DBA of it against your bike, I also have a DB meter I use at work if you want to see the true difference in sound level.
 Bob

[cruzziguzzi]

Seems that everybody on every forum wants to talk about how to make their bike louder...

I generally agree in that aftermarket exhausts tend towards louder rather than better - better as I see it anyhow.

I don't necessarily want mine to sound like sewing machines but would rather have quality of sound over volume. My little Sportster is horrible to me, my Carbi-Fornia suffers from a P.O. doing a hill-billy gutectomy on the factory silencers and my GS850G has something even JC Whitney wouldn't have sold.

In a perfect world, I'd find a way to make my bikes all sound like my old Norton 850 - it was as close a motorcycle as I've ever had to sound like my favored exhaust note - that of an American "big-block" burbling like a ski boat with the exhausts just barely under the water.

Now too, I recall my Valkyrie - there was a sweet exhaust note. Notable on the gas but never unduly "loud". That was one hell of a sound.

Another aspect of exhaust tone which I find important on my cars, trucks and bikes is that I want to hear a healthy induction sound, so when exhaust completely overrides this, I know immediately that the exhaust is "too loud".

I wanna hear that otherwise fresh air, roar in protest against what's about to happen to it.


Todd.

[Steph]

I think a motorcyclist can also register vibrations as noise in the brain. A bit like a uni-body car's road noise coming from the tyres noise transmitted up the shock mount into the car.

I think that's why even with wearing earplugs, my Cali Stone is prone giving me a good ringing in my ears.

[Rox]

 

Who buys a 90 degree v-twin guzzi and wants it to be as quiet as an electric bike?
Perhaps buying a Bonneville would of been better. With the stock pipes they sound like sewing machines..

[AH Fan]

In the second decade of the twenty first century anybody who believes that an performance advantage for road use can be achieved by making the engine/exhaust noisier is the sort of dull witted moron who should only be allowed out in the company of a responsible adult. This is particularly true of 8V Guzzis but the same holds true across the board.

If you want to be a noisy moron? Fine, but at least own up to it. Putting a noisy pipe or a rock-strainer air filter on your bike may alter the way the engine performs. It may even give you fractionally more outright horsepower at WFO but there will always be sacrifices along the way.

You'll also go deaf and end up as the sort of stunted, shouting half-wit that nobody wants to sit near in the pub because they're a noisy pain in the arse.

This isn't to say aftermarket pipes need all be a bad option. Far from it. its just that 'Loud' neither improves performance or saves lives. It simply singles you at as a dribbling idiot.

pete

Pete............... . next time/if your ever in the Vancouver area give me shout........ Ill supply the beer, your one funny F--k. 
              Cheers.   

[swordds]

Great idea using the dB meters!  I have one of those, what I don't have is a friend to use it. However my brother is coming to visit me next week so I will recruit him and I will test both my MG and my Suzuki TU250X and report back, probably not until Wednesday or Thursday and probably will report results in a new thread.

[Sheepdog]

As a confirmed motorhead I like to be able to hear the nuances of a power plant...things like the firing interval and the intake tuning add to the experience in my view. However, raspy, tinny, and really loud intakes/exhausts are irritating and, potentially damaging to a rider's (and adjacent person's) hearing. I like a rich and identifiable sound...not a din.

On the other hand, I wish I could make my 4-wheeler a little quieter. It sure seems to make a racket on the way to a deer blind...

[Joliet Jim]

Well based on this thread I'm a dim witted moronic asshole, but I'll keep the bubs on the centauro and the mistrals on the California. I like being heard because I think it's safer and I like hearing other bikes and more than once I've heard a motorcycle before I've seen it. If they put loud sirens on police, fire, and emergency vehicles, someone must think it helps them get noticed. Otherwise the flashing lights would be sufficient.

Just my opinion which is worth what you paid for it.

[Lcarlson]

I have an Akrapovic titanium can on my Beemer. The sound is much deeper than the stock muffler, but it isn't loud. Plus it saves close to 30 lbs and (according to Akra) provides a small increase in horsepower and torque. Also probably worth mentioning that BMW uses Akrapovic as OEM equipment on some of its high-performance models.

[Carlo DeSantis]

To my ears, the best sounding bike I've ever had was my '01 EV with H-Pipe, stock mufflers, and stock air intake.

Best,

Carlo

[Triple Jim]

My Mille's stock exhaust is as loud as I'm willing to go.  If I ever make any changes to that system, it'll be in the quieter direction.

[mtiberio]

I like my bikes quiet. That said I did once like loud pipes.

[Arizona Wayne]

My ears are already shot so I want to hear any vehicle around me in case we might cross paths by mistake if we didn't know each others whereabouts.    I wear foam ear plugs but can still hear good enough to notice vehicles around me unless they are BMW MCs.

Maybe you dislocated beemerphiles should move to Switzerland.  In the `90s I met some Guzzi riders from there @ Lake Tahoe and their Guzzis were so quiet I couldn't even tell they were running.  Switzerland sounds like your kind of place. 

[Nic in Western NYS]

Got the stockers put back on yesterday.  Glad I bought the bike with those thrown in.  Really improved the experience for me on the 2 hour ride over the mountains.  Great sound with throttle but no drone when not under increased load.  I found myself using more throttle going through the country roads where there are houses and farm animals with the quiet pipes.  Foam earplugs a must even with quiet pipes at speed.

[Dean Rose]

To my ears, the best sounding bike I've ever had was my '01 EV with H-Pipe, stock mufflers, and stock air intake.

Best,

Carlo

Yep


Dean

[swordds]

Well based on this thread I'm a dim witted moronic asshole, but I'll keep the bubs on the centauro and the mistrals on the California. I like being heard because I think it's safer and I like hearing other bikes and more than once I've heard a motorcycle before I've seen it. If they put loud sirens on police, fire, and emergency vehicles, someone must think it helps them get noticed. Otherwise the flashing lights would be sufficient.

Just my opinion which is worth what you paid for it.

OK, so I should get an airhorn from an 18-wheeler and connect it to a timer so it blasts every 30 seconds while I drive along?  That should make me safer?  Thers is loud and then there is too loud. If someone thinks it is too dangerous to ride a motorcycle unless they make themselves a public nusciance then they shouldn't be riding a motorcycle.  Anyway it is been a pleasure for me to hear from others that also appreciate a quiet motorcycle. Thank you. Who knows, one day some aftermarket exhaust manufacturer might even get the clue that some riders would consider quieter exhaust to be an improvement. Right now my exhaust system is certified to meet an 80 dB(A) standard (and I am assuming without yet having measured it that that is about the actual current noise level) which is OK but if there was an aftermarket exhaust system that certified or promised a noise level of 72 dB(A) I would consider that a worthwhile upgrade even with a marginal (2-5%?) decrease in dyno hp.

[Joliet Jim]

OK, so I should get an airhorn from an 18-wheeler and connect it to a timer so it blasts every 30 seconds while I drive along? 

No because at 60 mph you would travel .5 mile between blasts

[Arizona Wayne]

Maybe all you riders who want quiet bikes should switch to electric bikes.  No more mufflers to deal with.   

[Dean Rose]

Guys that's why they make Vanilla and Chocolate, everyone has an opinion. Ride what you want.


Dean

[jbell]

Maybe all you riders who want quiet bikes should switch to electric bikes.  No more mufflers to deal with.   

40 years ago I rode a Triumph 650 with straight pipes and Snuff-or-Nots.  No mufflers to deal with.  Man, was I a jerk.  Haven't changed much, just quieter.   

[Sheepdog]

To my ears, the best sounding bike I've ever had was my '01 EV with H-Pipe, stock mufflers, and stock air intake.

Best,

Carlo

This is pretty much how my Vintage is set up (though I did put three 1" Uni vents in my air box lid). It has a mellow sound with zero harshness. I've received several complements from folks on the muted, but throaty sound...

[Doppelgaenger]

When I was first shopping around for guzzis, I had the option of buying an 01 V11. One of the points that the seller made was to blast the throttle and make the bike roar. He thought it was amazing and a good selling point, it was one of the things that killed the sale for me.

I like the sound of my B11, and I think part of the reason is that it can roar when I want it to, but it's quiet most of the time. I think most of the sound that engine makes is actually induction noise and not exhaust. Which is the best kind of noise. I truly can't get enough of the sound of that engine at WOT around 5k rpm.

To me, the whole "loud pipes save lives" thing is actually true. A Harley or crotch rocket with an open exhaust will never be ignored. It'll be loved or hated, but never ignored. But there is always that clueless driver who will merge into your lane because they didn't see you, or hates your loud bike and is out to kill you on purpose. You have to ride like everyone is going to merge into your lane. Regardless of your rights, you can't win a court case when you're dead or mentally unfit to present evidence. If you have to be that loud, you likely have penis size problems or are an asshole. Likely both.

I really did enjoy the quiet of the Zero when I test rode one. The electric motor whine is pleasing to my ears, and the quiet while stopped at a light was a strange but welcome respite from the wind noise. Range, and in particular charging speed, are the only downsides to those bikes right now. Oh and let's not forget price.

[Steph]

On the Cali EV, if removing the air box cover makes more induction  noise then standard, would a thick rubber mat on top of the existing airbox lid effectively quiet down the roar?

[Arizona Wayne]

Another + for  loud(vs quiet) mufflers, when I come around a corner and see deer or elk looking at me on the sides of the road, I know they heard me coming before I saw them, and they usually scatter. 

[Vagrant]

On the Cali EV, if removing the air box cover makes more induction  noise then standard, would a thick rubber mat on top of the existing airbox lid effectively quiet down the roar?

I doubt it. the 2 snorkels coming out in front by the steering head are the issue. the Stelvio faces out the back of the passenger seat. much better design.

[swordds]

My sound measurements have been delayed by one week. Will try to run the tests during the week of January 18th, weather permitting.

[atavar]

Another + for  loud(vs quiet) mufflers, when I come around a corner and see deer or elk looking at me on the sides of the road, I know they heard me coming before I saw them, and they usually scatter. 

By your logic then we should all put metal playing cards in our spokes and have air raid sirens on the sissy bar.  Then you'd be really safe.

[keuka4884]

I am running airhead mufflers on my T3. The T3 has 40mm OD pipes and airhead mufflers come in either 38 or 40 mm. Had to make small adapters to bolt them on but I like them. They look like Dunstalls with a small upsweep. They were very quiet in the beginning but about 2000 miles later they have lost some packing and are somewhat louder now. Nice sound. Loud enough to get noticed but not loud enough to disturb anyone. And they look good on the bike. 

[Carlo DeSantis]

I am running airhead mufflers on my T3. The T3 has 40mm OD pipes and airhead mufflers come in either 38 or 40 mm. Had to make small adapters to bolt them on but I like them. They look like Dunstalls with a small upsweep. They were very quiet in the beginning but about 2000 miles later they have lost some packing and are somewhat louder now. Nice sound. Loud enough to get noticed but not loud enough to disturb anyone. And they look good on the bike.

Picture available by any chance?   Are they OEM BMW mufflers, or aftermarket?

Thanks!

Best,

Carlo