Hi Vance:
Well you do have a point. But I don't know about scaling with engine output.
The clutch on a motorcycle is typically about 4" across and the average big
bike has 100 hp. However I will grant you that mpg is not a major
consideration on motorcycles. I am not even a fanatic about wet clutches.
The point I do feel strongly about is that it is surely possible with a few
dollars extra to build some sort of clutch that can be repaired without
separating the transmission and engine. Unfortunately, due to market
pressure, manufacturers are not about to change this mechanism that so few
people even know exists. It just isn't enough of a early problem and
probably wouldn't be a sales feature. Car companies are more controlled by
actuarians than engineers. It is very hard to walk away from so much data.
They live by the motto, "Better the devil you know..."
I think my rant was more about having been stuck in the snow on my back a
few times with a variety of different cars and realising that they all had
one thing in common; the clutch. Well yes, the same ham-handed
mechanic/owner, but also the clutch. And red paint. Three things. Tires and
a windshield. Damn, five things! OK OK lots of things in common, but that
clutch thing really bugged me. Really. It finally drove me to swear that I
would never own another commuter car that was not an automatic. I have been
stuck in traffic jams with no clutch. At the top of Mount Royal with no
clutch. I drove a Renault Alliance on a 1000 mile trip city and highway
once with no clutch. (I really learned to shift smoothly then!) Thankfully
my TR6 clutch rebuild, done about 3000 miles ago when I rebuilt my motor,
seems to be holding. Even so I have ordered my Gunst kit from Nelson Reidel
just to be ready when I have to pull my transmission to get my O/D working.
:^(
Cheers,
Mark
-----Original Message-----
From: Navarrette, Vance [mailto:vance.navarrette@intel.com]
Sent: Thursday, December 19, 2002 5:28 PM
To: 'Mark Hooper'; 'Jim Swarthout'; 6pack@autox.team.net
Subject: RE: TRF magic clutch kit
Mark:
Interesting rant. I am not certain I agree with the overall
thrust of the diatribe, however.
The fact that the basic concept has been around for so long
speaks to me of it's reliability and low cost, not it's lack thereof.
Wet pack clutches have not scaled well with engine output, as the
power losses increase pretty dramatically with increases in size.
I am sure that there have been some bad designs over the years,
but the car magazines still prefer manual transmissions with
dry clutches in terms of flexibility and performance. The top dog these
days is the BMW 5 series with a manual single disc dry clutch, a 100
year old anachronism in a fuel injected state of the art automobile.
Just like the internal combustion engine, some things are still with
us because they work well, and are less expensive than the alternatives.
As for ease of service, the trend appears to be pushing in the
direction of decreasing maintenance frequency and cost, even if it means
increased costs when service finally is required. This is what consumers
seem to want.
If things were really as bad as you suggest, I believe that the
car manufacturers would have long ago abandoned the use of dry clutches.
Just my opinion....
Vance
------------------------------
1974 Mimosa Yellow Triumph TR6
Cogito Ergo Zoom
(I think, therefore I go fast)
-----Original Message-----
From: Mark Hooper [mailto:mhooper@pixelsystems.com]
Sent: Thursday, December 19, 2002 12:51 PM
To: 'Jim Swarthout'; 6pack@autox.team.net
Subject: RE: TRF magic clutch kit
Jim:
Clutches! That touches a sensitive point. Who hasn't spent a session or two
anxiously lying on their back peering at the underside of the car wondering
how they were going to get home. And then to realise that they would have to
practically disassemble the car to fix this $30 part.
<rant mode on>
I would say that the entire dry clutch design was not the automotive
industry's "finest hour". It comes from the dawn of time when parts were
expensive and everybody either had a chauffeur (1%)or did it
themselves(99%). Paying a mechanic at madison avenue lawyer rates is a
recent innovation that has forced manufacturers to develop disposable cars
that work perfectly for a while under warranty but then must be scrapped
because they cost more to fix than to replace. It was once very common to
reline your own clutch friction plates. Now the mechanic fees make such a
course unthinkable. You replace the entire mechanism just in case since it
would cost the entire amount again if the first attempt failed to fix the
problem.
It is absolutely outrageous that in 2002 we are using this 120-year old
idiocy. And in case anyone feels that it is a period design that shouldn't
have been updated, most motorcyles of the time had the "wet packed disc"
setup that allows the clutch to be removed and reinstalled in 30 minutes,
with most of the time spent cleaning the crankcase up all without ever
touching a hair on the installation or connection of the transmission or
engine. Almost any number of designs were doable with a wet clutch and were
commonly deployed in other machines. It is only the desire to save $2 at the
expense of the motorist that has kept this anachronistic abomination on the
road to this day. A wet clutch is smoother, simple to repair and doesn't
smell or rust shut have worn through finger springs.
It seems that even today, the car manufacturers aren't interested in fixing
the design. The newest cars are not much changed in this area from their
ancestors of 4 generations past. Better materials applied to a concept that
was old before it ever saw the light of day in the 1800s.
<rant mode off>
Mark
-----Original Message-----
From: Jim Swarthout [mailto:jswarth1@tampabay.rr.com]
Sent: Wednesday, December 18, 2002 11:42 PM
To: 6pack@autox.team.net
Subject: RE: TRF magic clutch kit
To the list,
Please forgive my ignorance!
Until my recent purchase...I had not owned a TR-6 for over 10 years.
I closed my shop 12 years ago.
I never had any problems with release bearings!
I changed many clutches for customers...and not one came back!
Nothing could be simpler, (by design), than a clutch release bearing!
If this is truly a problem, then I would suggest we all attempt to find
out why!
This must be an obvious blunder on the part of the manufacturer!
Considering the amount of labor that is required to change the release
bearing, I would have been highly irritated at having to repeatedly
replace release bearings for good customers.
Answers to these questions are never a mystery...there must be an
obvious reason why these bearings are failing.
Jim Swarthout
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