SuzukiSavage.com - Thumper......What qualifies?

Dave

YaBB Moderator
ModSquad

Offline

SuzukiSavage.com
Rocks!

Posts: 18099
Camp Springs, Kentucky
Gender: male

Thumper......What qualifies?
10/07/14 at 06:20:42

A few days ago someone posted about a 250 Thumper chopper. Now I am beginning to wonder.....at what point does a single cylinder bike qualify as a 'Thumper"?

Personally I have applied the Thumper term to a 500cc and above singles - but not for anything smaller....and never for a 2 stroke bike. Maico used to make a 501cc single cylinder 2 stroke....and it made a "Braaaap" sound....never "Thump....Thump....Thump".

Does a 100cc bike that makes "Putt....putt....putt.....putt" sounds quailfy as a Thumper????? I think not!

What are the rules of conduct? How should be behave?

Back to top

Someday I will be old......But not today!

IP Logged

thumperclone Serious Thumper Alliance Member Offline PGR rider riding with respect Posts: 6067 Grand Junction Colorado Gender:	Re: Thumper......What qualifies? Reply #1 - 10/07/14 at 07:31:23 any single cylinder 4 stroke motorcycle
Back to top	standing for those who stood for US IP Logged

justin_o_guy2 Serious Thumper Offline What happened? Posts: 55279 East Texas, 1/2 dallas/la.	Re: Thumper......What qualifies? Reply #2 - 10/07/14 at 07:47:17 Nah,I'm with Dave, at some point the term no longer applies. If I was gonna get serious about it,stroke length and RPM would probably be part of the equation, but if an engine isn't big enough,single or no,Snot a thumper. AND,TC,no matter how many times you say it is won't Chaaaangemymind,,,,
Back to top	The people never give up their liberties but under some delusion.- Edmund Burke. IP Logged

bobert_FSO

Senior Member

Online

SuzukiSavage.com
Rocks!

Posts: 421
Wichita KS
Gender: male

Re: Thumper......What qualifies?
Reply #3 - 10/07/14 at 07:47:35

I would say certainly down to about 175-250cc. Really about any displacement where one starts to have the option of choosing a multi-cylinder engine. Maybe the threshold is relative. Back in the '70's or '80's, I think Honda had a 175cc twin and a 175cc single. At that point, I think the single qualified as a thumper.

500cc is a little high for qualification. My BSA 440 was certainly a thumper compared to other bikes of the era.

Back to top

IP Logged

justin_o_guy2 Serious Thumper Offline What happened? Posts: 55279 East Texas, 1/2 dallas/la.	Re: Thumper......What qualifies? Reply #4 - 10/07/14 at 07:49:17 Should torque be a factor?
Back to top	The people never give up their liberties but under some delusion.- Edmund Burke. IP Logged

bobert_FSO Senior Member Online SuzukiSavage.com Rocks! Posts: 421 Wichita KS Gender:	Re: Thumper......What qualifies? Reply #5 - 10/07/14 at 07:50:20 Dave, if you watch the crankshaft in your video, that engine is some kind of two-stroke. It looks and sounds to be firing on every crank revolution. It's also possible it is a two-cylinder.
Back to top	IP Logged

Dave

YaBB Moderator
ModSquad

Offline

SuzukiSavage.com
Rocks!

Posts: 18099
Camp Springs, Kentucky
Gender: male

Re: Thumper......What qualifies?
Reply #6 - 10/07/14 at 08:21:46

bobert_FSO wrote on 10/07/14 at 07:50:20:

Dave, if you watch the crankshaft in your video, that engine is some kind of two-stroke. It looks and sounds to be firing on every crank revolution. It's also possible it is a two-cylinder.

Yea, that is certainly possible. Some of the big engines were two stokes. The Reid engines were 2 strokes and used a charging cylinder to pull natural gas from the oil wells, and use that for the fuel to run the engines.

Back to top

Someday I will be old......But not today!

IP Logged

Dave

YaBB Moderator
ModSquad

Offline

SuzukiSavage.com
Rocks!

Posts: 18099
Camp Springs, Kentucky
Gender: male

Re: Thumper......What qualifies?
Reply #7 - 10/07/14 at 08:29:27

justin_o_guy2 wrote on 10/07/14 at 07:49:17:

Should torque be a factor?

To me....the exhaust note is the issue. Thumpers got the name from the sound they make . When big singles are idling they go Thump....Thump....Thump....and even when accelerating they just bunch the "Thumps" up closer together.

When the engine is so small it no longer "Thumps".....then it ceases to be a Thumper. Things that go "Putt"....."Pop"......"Tutt" might not qualify...and when the Thump turns into a steady Buzzzzzzz at speed???????.

And Yes....a 440 Victor certainly would qualify as a Thumper.

Back to top

Someday I will be old......But not today!

IP Logged

stewmills

Serious Thumper

Offline

Imagination is more
important than
knowledge

Posts: 2641
Auburn, AL
Gender: male

Re: Thumper......What qualifies?
Reply #8 - 10/07/14 at 08:37:43

Maybe we should come up with an equation using several factors:

T= torque
V= volume (cc)
Db= Decibels
F= Frequency (of the thump, thump, thump)

((T)x(V)+Db)) / F is >/= X (must be greater than or equal to X)

Now what X is, I have no clue because I don't know what the stock values would be for the above variables but I'm sure one of you wise guys will solve the equation here shortly Grin

Back to top

IP Logged

Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28660 Tucson Az Gender:	Re: Thumper......What qualifies? Reply #9 - 10/07/14 at 09:18:46 Too complicated... I call any 4-stroke single, a thumper,... any over 400cc,... a big thumper... JMHO...
Back to top	Ludicrous Speed !... ... ... IP Logged

stewmills Serious Thumper Offline Imagination is more important than knowledge Posts: 2641 Auburn, AL Gender:	Re: Thumper......What qualifies? Reply #10 - 10/07/14 at 09:30:12 I'm just teasin'. Still waiting on someone to try and figure it out though
Back to top	2008 \| 152/52.5–Air Mix 3/4 \| Rotella T4 \| Seat Lift w/Sheepskin \| Speedo Rattle \| Rear Pulley Shim \| 140/90-15 Rear \| Kaw Front Pulley \| Relocated Rear Signals FREEDOM ISN'T FREE! IP Logged

Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18099 Camp Springs, Kentucky Gender:	Re: Thumper......What qualifies? Reply #11 - 10/07/14 at 09:59:30 I posted this just for a bit of fun...on a rainy day. I really didn't expect to come up with an empirical equation to define the Thumper. The weird thing is that just about every single motorcycle idles at about the same speed - but the tone of their voice sure changes with the engine size.
Back to top	Someday I will be old......But not today! IP Logged

justin_o_guy2

Serious Thumper

Offline

What happened?

Posts: 55279
East Texas, 1/2 dallas/la.

Re: Thumper......What qualifies?
Reply #12 - 10/07/14 at 10:09:59

stewmills wrote on 10/07/14 at 08:37:43:

Maybe we should come up with an equation using several factors:

T= torque
V= volume (cc)
Db= Decibels
F= Frequency (of the thump, thump, thump)

((T)x(V)+Db)) / F is >/= X (must be greater than or equal to X)

Now what X is, I have no clue because I don't know what the stock values would be for the above variables but I'm sure one of you wise guys will solve the equation here shortly Grin

Man, I gave up huntin for "X" in Algebra.. Now, if you want me to go looking for "X", you gotta hand me a treasure map.

Back to top

The people never give up their liberties but under some delusion.- Edmund Burke.

IP Logged

Greg

Serious Thumper

Offline

Molon Labe

Posts: 1251
Southeast PA, uSA
Gender: male

Re: Thumper......What qualifies?
Reply #13 - 10/07/14 at 10:32:24

There are currently 125cc twins available overseas. I like the idea of where an additional cylinder is added as being the cut off. In my mind, that would be 125cc and higher. A 4 stroke is a must as well.

bobert_FSO wrote on 10/07/14 at 07:47:35:

I would say certainly down to about 175-250cc. Really about any displacement where one starts to have the option of choosing a multi-cylinder engine. Maybe the threshold is relative. Back in the '70's or '80's, I think Honda had a 175cc twin and a 175cc single. At that point, I think the single qualified as a thumper.

500cc is a little high for qualification. My BSA 440 was certainly a thumper compared to other bikes of the era.

Back to top

2002 Savage.

IP Logged

Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18099 Camp Springs, Kentucky Gender:	Re: Thumper......What qualifies? Reply #14 - 10/07/14 at 10:39:05 Good thing we aren't accepting 2 strokes....then the discussion would have to include the Twingle! A Single combustion chamber and spark plug, on a single crankshaft bearing.....that has two pistons and connecting rods. http://en.wikipedia.org/wiki/Split-single
Back to top	Someday I will be old......But not today! IP Logged