Large driveshaft?

[Steve in Golden]

I saw an ad on Craigslist for an '82 R100. He mentions that it has a "large driveshaft". What the heck is he talking about? Did some airheads come with small, some with large driveshafts?

1982 BMW R100. Rebuilt Final drive, forks, carbs. Spline Lube. Fresh Oil. Great Shape. Not perfect but a great old Beemer. 40mm bings, big valves, large Drive shaft. Good Rubber. Bmw system cases. $3,000.00

http://denver.craigslist.org/mcy/1930983210.html

[Deleted User 61]

I hope it fits in the swingarm, O.K!

They only came in a variety of lengths, AFAIK. Solid & spring cush. Nothing you didn't already know, I'm sure.

[Garnet]

Sometime around 79 or 80 airheads came with a cush drive built into the shaft. The swing arm tube is much larger than the /5/6 and early /7.

I think it coinsided with the first rear disc but my memory is fuzzy.

[Max Headroom]

I saw an ad on Craigslist for an '82 R100. He mentions that it has a "large driveshaft". What the heck is he talking about? Did some airheads come with small, some with large driveshafts?

1982 BMW R100. Rebuilt Final drive, forks, carbs. Spline Lube. Fresh Oil. Great Shape. Not perfect but a great old Beemer. 40mm bings, big valves, large Drive shaft. Good Rubber. Bmw system cases. $3,000.00

http://denver.craigslist.org/mcy/1930983210.html

It's probably got the later twin-shock swingarm, which is more commonly referred to as the "big-tube" type. Stiffer than previous types, so it's preferred by those seeking better handling.

[vanzen]

"Large Drive Shaft" is likely a reference to the drive-shaft tube diameter –
which was changed in '81 ( I believe ) to increase stiffness of the SA.
I also seem to remember that dampened drives were used previous to the SA diameter change.
I do know for a fact that dampened drive shafts and straight shafts are interchangeable –
i.e. the same length & splines.
The change from cush to straight is popular in racing for an unsprung weight savings.
Large diameter SAs are also interchangeable with earlier SAs,
and a popular retrofit if one should want less flex from the SA without adding braces.

[robtg]

In my opinion the best combo is the late large diameter swingarm and the early undampened driveshaft. The dampened shaft combined with the trans input shaft damper makes it feel like the throttle cable has been replaced with a rubber band.

[Steve in Golden]

Oh yeah I had forgotten about the larger diameter swing arms, thanks for reminding me guys. Poor choice of verbiage on the seller's part if you ask me.

It is a nice looking bike though isn't it. Mebbe I should go look at it. 'cept it's the wrong color - motorcycles should be black .

[vanzen]

In my opinion the best combo is the late large diameter swingarm and the early undampened driveshaft. The dampened shaft combined with the trans input shaft damper makes it feel like the throttle cable has been replaced with a rubber band.

Agree. But for me a decision based exclusively upon the goals of performance.
(early '80s trans, mid '70s straight shaft, '92 mono SA)
On the flip side, however,
the rubber band experience will be the price to ensure component longevity
by dampening the shock of that infernal bane of mechanical efficiency – "lash".

[Major Softie]

I believe you may all be misinterpreting the author's intent. If I am correct, "large drive-shaft" is a euphemism, and the author is suggesting that ownership of his motorcycle will have certain "enhancing" properties. Either that, or it is a challenge that one should already be so endowed to measure up to the quality and performance of this machine.

[Steve in Golden]

I believe you may all be misinterpreting the author's intent. If I am correct, "large drive-shaft" is a euphemism, and the author is suggesting that ownership of his motorcycle will have certain "enhancing" properties. Either that, or it is a challenge that one should already be so endowed to measure up to the quality and performance of this machine.

I'm going with option #1.

And in that case, I guess I will delete the "male enhancement pills" e-mails I've been perusing and go buy it! 3 grand is a bargain for a bigger tallywhacker.

But wait...

Mine's already pretty big, if it got any bigger no woman could accommodate me. I guess I'd better hold off.

Hmm. If we're not careful the moderators might move this thread to the Speakeasy!