Rocket bore/stroke,vs. HD bore stroke

[ski]

I must admit, I like the throaty sound of an open exhaust on a Harley. The Bore and Stroke on a Harley 1690cc is 98.4 x 111.1 mm or 3.874 x 4.374 inches.
The Rocket is 101.6 x 94.3 mm or 4. x 3.7126 inches.
So The bore on the Rocket is .126 larger than the HD.
The stroke on the Rocket is .661 shorter than the HD.
Is the longer stroke on the HD the only thing that gives it its deep bass sound?

It seems this relativity small difference between the the two cylinders shouldn't make that much sound difference in explosions inside the motor between the Harley and the Rocket.
Now, I DON"T want the Rocket to sound like a Harley. That is not the point of this conversation. I am only asking a technical question.

 

[Rocket Scientist]

I think valve timing combustion chamber shape, long stroke and the massively uneven firing order of a Harley engine is what gives it it's sound. If you go back some years the knuckle/pan/shovel era Harley's had a much deeper, throatier sound, primarily due to the Porsche designed heads on the Evo's on up.

 

[ski]

Back in 1979, I was riding a 1200cc HD with open pipes. When the 1340cc came out, Harley offered a kit to turn your 1200 into a 1340. New jugs, pistons, heads etc. Over the winter I installed the kit. The first time I kicked her over, the deeper note was very noticeable. I think my neighbors noticed also, as the anonymous death threats increased substantially.

 

[zenbiker]

Of course you want it to sound like a Harley! It's the best sound in motorcycling! 52 degree firing irregularly gives it the "lope"
Never out of anything but a V twin with a single crank pin.

 

[ski]

Of course you want it to sound like a Harley! It's the best sound in motorcycling! 52 degree firing irregularly gives it the "lope"
Never out of anything but a V twin with a single crank pin.

Your right about one thing. All the other bikes out there with loud deep sounds don't come close to the sweet sound of the Milwaukee machine.

 

[zimtuff]

A lot of HD owners love the sound of my R3 with Jards at 3-4000rpm. Old lady up the road loves the way her crockery rattles in the cupboard when I come down the street.
I used to like the sound of HDs but after a while when you understand they are only making 75hp with all that noise it becomes a little underwhelming.

 

[ruzzle]

It's not potato-potato, it's just your typical old longstroke chug-chug. My 1956 Massey Ferguson with straight pipe sounds much the same

 

[zimtuff]

Is the MF a one owner? LOL

 

[warp9.9]

Harleys are actually quite most of the time since they ar ebroke down and your pushing them on a Trailer. Other then that a double thumber and a Inline four will always sound different from the triple.

 

[TOMCAT]

I actually find the racket that comes out of an un-baffled Harley ***cin annoying as hell. Rode all the way from Darwin to Melbourne with a V-Rod muscle running Vance + Hines exhaust .. it was one of the worst sounds I've ever heard a motorcycle make .. and that includes 2 strokes