Thumper or not ?

[Fil]

[Garf]

Well, I didnt think my query would cause so much debate !!

Personally I will still refer to my bike as a Thumper as I believe that the term has evolved by popular (mis?) usage to refer to any large capacity single cylinder motorcycle engine.

I can see that historically, as Bill argues, that the term would have probably have been originally coined to describe the low revving, long stroke low compression motors of yesteryear but is that just because most of the larger 4 strokes around when it was first used happened to have engines configured in that way ?

Had our engines been around when the term was first used then I suspect that they would still have been lumped in the same 'category' simply by virtue of the basic design similarities to all the other bikes ie single cylinder and large capacity 4 stroke.

Anyway guys, great input I have enjoyed reading this thread.

Cheers
Garf

[Bill Jurgenson]

well, no, it is and was because those engines "thumped," really thumped. It didn' thave much to do with displacement and a 350 was a thumper, too. The engines we all use do not thump or do anything even approaching that.
Heavy vibes maybe, but no thumping. That can't even idle at speeds those real thumpers operated at.

[keithcross]

Please guys, dont argue with Bill on this one, he is right. In fact he is always right on everything.

Keith

[Garf]

Well, my biking started around 1980 and has exclusively been on Jap twins and 4's so compared to anything have owned or ridden my MZ certainly feels like it thumps.

I hope that sometime I might get to ride something that Bill would class as a thumper then perhaps I would better understand the distinction he makes.

Up until then I am happy enough to continue rightly or wrongly, to refer to my bike as a thumper.

At the end of the day, although interesting to discuss it isnt really of any importance. Surely the main thing is that we all love riding these great bikes.

Garf

[Bill Jurgenson]

[Old Dog]

I thought I might chip in my 2 cents worth and say that I have to agree with Bill on this one. Sometimes one does ride one's bike a certain way because it is suggested. I started riding my Tour as Bill recommended and it completely transformed what was previously a bike that I never totally got along with. Now that I ride it like a my old 2T MZ that is keeping the revs up 4.5 -6.5, I find that all the things I didn't like about it are no longer relevant.

I also ride a 500 bullet which is a thumper and once you have tried the real thing, you quickly realise what Bill is on about. The fact that both are large capacity singles is irrelevant, the Bullet is a thumper, it thumps, revs low and will pull in top from just above idle if neccessary, try that on a Skorpion or an XT and you'll be lucky if it doesn't put you on your arse. That said if you ride the bullet like Bill recommends you ride a 660 you will not find a rewarding experience, it gets up there in its own time by building up, building up. You can feel the flywheel momentum.

As to whether you want to call the 660 a thumper well that I guess is purely a matter of preference, people call things all sorts of things but it doesn't make it so...

Cheers

OD

[Fil]

[Nozz]

Now that we are talking more about suggested rev ranges. I have the Rotax 500 on a Silver Star, and was advised from day one not to ride at too low a rev. The practical range seems to be from over 4000 to 6000-6500, and it feels "bogged down" running much below 4000. Other than just feeling better at the higher rpm, what effect does it have on the engine, etc.?

Secondly, at first glance I thought this was kind of frivolous discussion and was biased towards thinking they are all thumpers. Now I appreciate the difference a little more and we can all discuss it with a bit more authority "out there" among the non-MZ world in which we are so blessedly outnumbered!

Thanks to everyone for sharing your insights and comments.

-Jim in Austin TX

[DAVID THOMPSON]

I have the Rotax 500 on a 95 Saxon tour
i use the spark plug DPR8EA-9 ori was d8ea
runs and idles much better

mine idles at about 1500 rpm and seems to pull good from 3000 up
i seldom run faster than 65 mph on it
town use most of the time 3000 rpm to 4500 rpm
below 2500 it gets to doing the jerk jerk thing on the chain

nice running bike after it got worn in and i changed the plug

20,000km on it now = 12,427 miles
a note for NOZZ the stock sprocket on mine at the engine was 18 tooth
i went to 17 and it does much better in town and on the highway
ar dave