General Biking Discussion Approved.

thanx aryan

good question yaar...didnt strike me...here is what i found out in bits and pieces.

They're called "thumpers"Single cylinder motorcycles, generically know in the U.S. as "thumpers", have been around for as long as there have been motorcycles, and there has always been a certain charm, a certain panache, a certain charisma surrounding them. Some say it is because of the ultimate simplicity of the engine, others are engagedby the unique sound emanating from them as they "thump, thump, thump" along Still others are enamored by the compact engine and light chassis that are part and parcel of a one-cylinder motorcycle.

in short

A thumper is a motorcycle powered by a large capacity single-cylinder 4-stroke engine, so called due to the thump-thump-thump sound the engine makes.
Thumpers have good low-end power and are most often dirt-oriented bikes or dual sport motorcycles.

do let me know about some more info.

thanx yaar

your post was quite helpful but still not satisfied...wanna know more details, CALLING ALL TECHIES!!

c'mon guys....no one knows anything about the topic???

is this a gimmick or something...
?

You want to know why single cylinder engined bikes like the Bullet are called thumpers? They thump that's why!

Is nt it! Thats what i think as well

What exactly you wanna know about thumpers?
Ask us..

it isnt exactly a technical term. more of slang rather than anything else. and there isnt much more to explain.

You want to know more about the Thumpers?
Visit The Thumper Page

arrre guys....i simply want to know WHY DO THEY THUMP??

Thumpers are defined as high capacity single cylinder motorcycles. Both of these traits give it its characteristic sound.

The primary source of sound in a thumper is its exhaust note, so all points below revolve around exhaust.

1. Low pitch (also explains why exhaust note doesnt seem as continuous as non-thumpers)

a. Single Cylinder: Since only one cylinder is performing all 4 strokes of the engine cycle, the exhaust gases escape only once every 4 strokes of the piston or two revolutions of the crank. When compared to a twin cylinder engine which will have 2 exhaust strokes with in the same time at the same rpm. Frequency is inversely proportional to time, so the longer it takes between the two sources of sound, the lower the perceived pitch.

b. High Capacity: The fact that a thumper has to compress a greater volume of air fuel mixture at once during a compression stroke than a low capacity single cylinder or an equal capacity twin means that it faces more resistance, leading to a slower running engine. This slower running engine means less rpms and hence less exhaust strokes per minute leading to a lower pitch exhaust.

2. Volume (of sound) (also kind of explains boom-iness):

a. High Capacity: Since the engine has to exhaust a larger amount of exhaust gas from the engine in a relatively short amount of time, exhaust gases tend to exit with greater speed. THis is perceived as a louder tone than the exhaust from a lower capacity engine (im not sure if this is right, someone please verify).

^^^thanx man!!

now i know