Author Topic: Slipper Dry Clutch  (Read 22314 times)

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Offline Tintop

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Re: Slipper Dry Clutch
« Reply #50 on: August 25, 2011, 12:40:59 PM »
You are a man of many talents mec.  Congrats on the table soccer championship. 8)
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline lucky

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Re: Slipper Dry Clutch
« Reply #51 on: August 25, 2011, 12:41:24 PM »
A really good project.
Now the engine may last longer too without the clutch materials floating around in the engine oil.

Offline Godffery

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Re: Slipper Dry Clutch
« Reply #52 on: August 25, 2011, 10:44:58 PM »
Thanks for the update man. fantastic work!!!

Offline mec

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Re: Slipper Dry Clutch
« Reply #53 on: October 01, 2011, 08:15:10 AM »
hi all,

there are good and bad news:

good first.
we had a race in Rijeka. my friend Robert was driving my racebike and everything went fine. despite the fact that my engine has some oil leaks (i believe all of them as a result of the thin cylinder walls, a well known problem with all the overbore sohc´s) it performed well. the clutch works fine.
this time I had the "rack element set" incorporated, the clutch set to its softest setting.
starting the engine with the paddock starter was no problem (however there was one start I could hear the clutch slipping. I think this was my own fault, because i mounted the heels with a tiny bit of copper paste which is way too stiff. now i reasembled all with low viscosity oil). under racing the clutch did what it was supposed to do: you never mentioned any nasty behavior of the bike under hard braking and shifting.

all in all we did 12 practice sessions á 20min and two races. maybe this corresponds to 10.000km normal street driving :)

one thing I have to mention: the hub (holding the outer clutch basket) has some play on the primary drive shaft. more than I can bear. this was when I goofed and tried to make a perfect fit on the primary by hand. to make it short, in winter I will have this hub made new. interesting is, that this hub incorporates the small shaft seal and the gasket surface for the big oil seal. despite beiing the hub "out of tolerance" the shaft seals are completely leakproof, the clutch is completely dry.

bad news:
unless there are important news this thread comes to an end.


I hope I have encouraged one or the other reader to try to realise his wildest dreams. everything is doable. just do it.

feel free to ask, have a good time

mec
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Massey Ferguson

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Slipper Dry Clutch
« Reply #54 on: October 01, 2011, 08:36:57 AM »
Mec,

It's been great! I'm looking forward to your next project. Guys like you will never quit  ;)

Jerry
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline lucky

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Re: Slipper Dry Clutch
« Reply #55 on: October 01, 2011, 09:13:05 AM »
Why would you want to convert this clutch?
Have you ever heard a Ducati dry clutch? Makes a lot of rattling noise and sounds like it is grinding up something. Horrible noise!

Can you tell me what the advantage is?

BTW...Thanks for the great thread and all the work you did to show us your project.
You are very fortunate to have machinists that can make your parts.

I did a similar project on a Kawasaki to make it chain drive instead of shaft drive and getting any shafts made or specification of splines was almost impossible. And it was going to cost $3000.00 dollars. I gave up and found another solution.
Just getting the splines specified cost me $700.00 !!!!

You may solve your hub problem the way I solved mine.
I cut the hub out of a stock part and then pressed fit it into my machined part with a interference fit and then TIG welded the two parts together. Worked perfect and was low cost.
« Last Edit: October 01, 2011, 09:31:03 AM by lucky »

Offline MRieck

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Re: Slipper Dry Clutch
« Reply #56 on: October 01, 2011, 09:34:34 AM »
Why would you want to convert this clutch?
Have you ever heard a Ducati dry clutch? Makes a lot of rattling noise and sounds like it is grinding up something. Horrible noise!

Can you tell me what the advantage is?

BTW...Thanks for the great thread and all the work you did to show us your project.
You are very fortunate to have machinists that can make your parts.

I did a similar project on a Kawasaki to make it chain drive instead of shaft drive and getting any shafts made or specification of splines was almost impossible. And it was going to cost $3000.00 dollars. I gave up and found another solution.
Just getting the splines specified cost me $700.00 !!!!
I'll chime in. The big advantage is no clutch fiber residue floating around in the oil. When racing there is a lot of clutch slipping at the start/ clutchless shifts and crud builds up quickly. They are noisy but so are flatslide carbs.
 I did a Kawasaki Eliminator years ago and wanted to convert it to chain or at least get a beefier drive shaft. I concur....it was expensive. ;)
Owner of the "Million Dollar CB"

Offline mec

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Re: Slipper Dry Clutch
« Reply #57 on: October 01, 2011, 10:12:33 AM »
Why would you want to convert this clutch?
Have you ever heard a Ducati dry clutch? Makes a lot of rattling noise and sounds like it is grinding up something. Horrible noise!

Can you tell me what the advantage is?


yes, i have heard ducatis..........see my first post :), its music in my ears!

take a look at the race tracks: if you see bikes that are REALLY fast, then they have dry clutches (Moto2, MotoGP).

advantages:
dry clutches can be made smaller and lighter.....less weight to be accelerated and slowed down,
you can use oil whatever you want and do not have to take into account your clutch,
all the dirt that comes from your clutch will stay outside the engine,
tuning your clutch is easy and will take less time (often necessary on racetracks),
heat produced by your clutch will not heat up your engine oil,
a dry clutch does not rotate in the engines oil sump (drag reduces power output),

something forgotten?

mec
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Massey Ferguson

Offline lucky

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Re: Slipper Dry Clutch
« Reply #58 on: October 01, 2011, 12:37:29 PM »
Why would you want to convert this clutch?
Have you ever heard a Ducati dry clutch? Makes a lot of rattling noise and sounds like it is grinding up something. Horrible noise!

Can you tell me what the advantage is?


yes, i have heard ducatis..........see my first post :), its music in my ears!

take a look at the race tracks: if you see bikes that are REALLY fast, then they have dry clutches (Moto2, MotoGP).

advantages:
dry clutches can be made smaller and lighter.....less weight to be accelerated and slowed down,
you can use oil whatever you want and do not have to take into account your clutch,
all the dirt that comes from your clutch will stay outside the engine,
tuning your clutch is easy and will take less time (often necessary on racetracks),
heat produced by your clutch will not heat up your engine oil,
a dry clutch does not rotate in the engines oil sump (drag reduces power output),

something forgotten?

mec

OK...ok I understand now ,many advantages.
Something forgotten...What about that hub making idea?

Offline mec

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Re: Slipper Dry Clutch
« Reply #59 on: October 02, 2011, 10:35:03 AM »
OK...ok I understand now ,many advantages.
Something forgotten...What about that hub making idea?

hi,
your hub making idea is really good.
but i doubt that it would work in my special case.  both shaft seal surfaces and the area where the outer clutch basket has to be screwed on must run absolutely concentrical to the inner toothing. sure, your idea could work for me, but price and time consuming work will be equal to make a new one.
thanx for your good input.

mec
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Takeuchi TB 070
Massey Ferguson

Offline d1000rr

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Re: Slipper Dry Clutch
« Reply #60 on: October 02, 2011, 07:30:11 PM »
That is pretty F'n awesome!!!!!!!!!!!!!!!

Offline 754

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Re: Slipper Dry Clutch
« Reply #61 on: January 23, 2012, 09:33:48 PM »
 bumping this up for TEWSday.....TEWS19.. was looking for the EGLI BUILD...
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline mec

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Re: Slipper Dry Clutch
« Reply #62 on: January 26, 2012, 12:18:57 PM »
funny thing:

in the januar 2012 issue Nr1 of MO-motorrad magazin there was a 4 pages story of my dry clutch conversion.

in the februar issue Nr2 i found one letter to the editor. the author complained that i violated the origin and tecnical superiority of this fabulous superbike of its age. i am missing the required respect and devaluated the value of the bike. this comes equal to a circumcision.

this made me smile.
what do i think? yes, he is right as i am right too. i am trying to make a fast vintage bike faster, thats all.

mec
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Offline Bankerdanny

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Re: Slipper Dry Clutch
« Reply #63 on: January 26, 2012, 02:00:56 PM »
I suppose I could see his point if it was a clean original street bike, or an original racer with some special past (a Freddie Spencer championship bike or something like that). But yours is an active racer and your mod was made to improve it as such. So I think he is very wrong.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

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Offline Syscrush

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Re: Slipper Dry Clutch
« Reply #64 on: January 26, 2012, 02:24:04 PM »
I think that we need the purists and the modifiers.

Just like we need artists AND curators, authors AND librarians.

But my god, there were zillions of these bikes made/sold.  It's hard for me to feel like the world has lost something special when a CB is modified with the level of care, skill, and attention that went into yours!
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline Retro Rocket

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Re: Slipper Dry Clutch
« Reply #65 on: January 26, 2012, 03:31:36 PM »
funny thing:

in the januar 2012 issue Nr1 of MO-motorrad magazin there was a 4 pages story of my dry clutch conversion.

in the februar issue Nr2 i found one letter to the editor. the author complained that i violated the origin and tecnical superiority of this fabulous superbike of its age. i am missing the required respect and devaluated the value of the bike. this comes equal to a circumcision.

this made me smile.
what do i think? yes, he is right as i am right too. i am trying to make a fast vintage bike faster, thats all.

mec

So, what did he say about that beautiful frame then...... :o   Good work Mec, if you are stirring up passion of any kind you are doing a good job.... :D ;)
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Offline 754

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Re: Slipper Dry Clutch
« Reply #66 on: January 26, 2012, 07:17:31 PM »
 Man what a jerk, cant he even at least acknowlede the effort and skill and expense  involved,.... EVEN if he did not support the clutch mod..
.. Its not like you commited a cardinal sin like leaving off the stock airbox AND running no filter...
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline ozcaferacer

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Re: Slipper Dry Clutch
« Reply #67 on: April 29, 2012, 10:33:31 PM »
the author complained that i violated the origin and tecnical superiority of this fabulous superbike of its age. i am missing the required respect and devaluated the value of the bike. this comes equal to a circumcision.
Hey mec, great work! Thanks for sharing your project.
BTW, I think I know what the author of that article looks like .....
It's cheaper to learn from someone else's experience but first you have to learn to tell the difference between a fact and a Furphy.

Offline Godffery

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Re: Slipper Dry Clutch
« Reply #68 on: April 30, 2012, 08:52:44 AM »

Offline KasperK/Denmark

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Re: Slipper Dry Clutch
« Reply #69 on: August 09, 2023, 05:58:30 AM »
Bedtime reading for multiple times  ;D
It’s a treat to us mortals to read and watch a conversion like this.
Thank you so very much.