Stupid clutch question

AFAIK, every bike I ever rode had a wet clutch except a WWII vintage
Harley. A friend tells me that dry clutches are common on bikes.
Have any of you ever heard of a 21st century bike with a dry clutch?

Michael

 

I know BMW and Ducati used to use dry clutches. I think they still do.

 

Ducati have Dry clutches in most of ther models range, but already
have some with wet clutches, it's easy to see if it's a wet or dry,
oly by the sound.

BMW don't have dry clutches, they are "wet", but they are like the
ones used in cars, use Valvoline.


The rest of japonese modern motorcycles are wet clutches, "maybe one
or another model isn't", and use the same oil as the engine, one of
the reasons why Ducati and BMW change oil ervery 10 000 kms, and the
others every 6000 kms because the clutch dust destroy's the oil.

Cheers
Jaime
Portugal
GSX-R 600 K4
WR426-F SM

 

??

'R' Boxer twins and 'K' longitudinal crank aka "flying brick" BMWs
have dry clutches. F650 F800, and the new transverse crank K(K1200R,
K1200S, K1200GT) bikes have wet clutches.

So I would say the majority of BMW bikes now on the road have a dry
clutch, but the future direction seems to be tipping in favor of
wet clutches.

 

As others have said: Guzzis, BMWs, Ducatis, plus Moto Morinis (Oh -
that's 20C really), and there's a smattering of small-production-run
homologated Japanese supersports bikes as well. Dry clutch conversions
are also common on race bikes.

 

Thank you (and everyone else) for the informative replies.
Now I have two more questions.

First, how do you tell by the sound? I know this is a fuzzy sort of
question, but maybe you can give me some idea.

Second, is there a difference operationally? I ask because the owner
of the Harley with the dry clutch told me not to operate the clutch in
partial engagement - either all the way in or all the way out. Now I
am used to being able to have partial engagement of the clutch on a
motorcycle if I need to go really slowly, or to make a very slow start
if I am tentative about something (the surface, for example) and it is
no big deal. The instructor at the motorcycle course made sure to
point out that it is not like a car clutch, this is OK to do. And the
owner of the WWII era Harley said that this was like a car clutch, so
don't do it.

I had always assumed that the wet clutch made it OK, maybe by moving
the heat around and not letting the clutch plates get too hot and
seize or warp, and the problem with doing the same with a dry clutch
was overheating the plates. But my friend also said that on a
motorcycle with a dry clutch, it's no big deal, ride the same way as
with a wet clutch.

So what am I missing?

Michael

 

You can with a Ducati. Their dry clutches rattle like hell. You can't
with most of the others.

Your instructor and the Harley rider are both idiots. What's wrong
with slipping a car clutch? And dry single-plate bike clutches (BMW,
Guzzi) are *exactly* like car clutches.

Your friend is quite right.

Some quality time with your friend, who knows what he's talking about.

 

Well, everything I ride has a wet clutch - Honda Valkyrie and Kawasaki
Eliminator are what I own now. My Kawasaki Vulcan had a wet clutch
too. So did everything that any of my friends owned. Like I said,
the only thing I ever rode that had a dry clutch was the ancient
Harley, and I thought the dry clutch was odd (many things about that
bike were odd - the gear shift was a lever on the left, for example).
The point was not - do I have a dry clutch. I know I don't. While
I'm an aircraft mechanic, not a bike mechanic, and aircraft don't have
clutches (usually - superchargers and air conditioners can, but the
aircraft I work on don't have those) I think I can still tell whether
I am working on a dry or wet clutch. I was just curious what does,
and what the difference would be from a rider's point of view. I
initially made the mistake of believing the antique Harley owner and
the motorcycle class instructor (also a Harley owner) and then I got
some contradictory information from my friend (who is a pretty damn
good mechanical engineer and mechanic, and thus ought to know) so I
wanted some additional input.

Michael

 

Slip it. Slip it good.