Clutch Slippage; part (enter your number here)

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Hi all, I had some issues with my race bike clutch initially and always thought it was because I was making a bit more power than the standard Commando motor.(My Roadster has a Maney belt drive and standard plates, easy lever pull and there is no slippage even with a load and pillion)
It has a 40 mm belt drive (therefore dry) and 1st gear is quite tall in the 5 speed close ratio gearbox.
It has all standard plates, steel and bronze, it is a Maney clutch basket (so not ultra light weight) and was very poor off the line and would slip once over 6400 rpm under load.
The lever pull was light, so I thought it was the motor power making it slip.
I tried putting in new bronze plates, no change, I cleaned it thoroughly with Brakekleen after every practice and every race, no change.Grit blasted the friction plates, no change.
Tried a different diaphragm, no change. Checked the stack height and plate thickness many times, all proving correct .
Checked for info on the forum , seems I had an older thicker pressure plate, so instead of buying a new one, I had it skimmed down close to the thinner plate specs. My diaphragm wasnt going concave enough at rest it seemed.
Now no slippage anywhere, still running all the same plate hardware, no slippage, will even pull a wheelie off the line at race starts.
the only thing that has changed is a slightly heavier lever pull , but that is fine at the expense of nil slip!
The bronze plates will do the business given everything else is right!!
Regards Mike
 
Brooking 850 said:
Hi all, I had some issues with my race bike clutch initially and always thought it was because I was making a bit more power than the standard Commando motor.(My Roadster has a Maney belt drive and standard plates, easy lever pull and there is no slippage even with a load and pillion)
It has a 40 mm belt drive (therefore dry) and 1st gear is quite tall in the 5 speed close ratio gearbox.
It has all standard plates, steel and bronze, it is a Maney clutch basket (so not ultra light weight) and was very poor off the line and would slip once over 6400 rpm under load.
The lever pull was light, so I thought it was the motor power making it slip.
I tried putting in new bronze plates, no change, I cleaned it thoroughly with Brakekleen after every practice and every race, no change.Grit blasted the friction plates, no change.
Tried a different diaphragm, no change. Checked the stack height and plate thickness many times, all proving correct .
Checked for info on the forum , seems I had an older thicker pressure plate, so instead of buying a new one, I had it skimmed down close to the thinner plate specs. My diaphragm wasnt going concave enough at rest it seemed.
Now no slippage anywhere, still running all the same plate hardware, no slippage, will even pull a wheelie off the line at race starts.
the only thing that has changed is a slightly heavier lever pull , but that is fine at the expense of nil slip!
The bronze plates will do the business given everything else is right!!
Regards Mike

It bears repeating: http://atlanticgreen.com/clutchpak.htm

and: http://atlanticgreen.com/ndnsclutch.htm

Thanks Dave!!
 
concours said:
Been there, done that. I even have the jacket! It helped initially, but found that the only long-term result was a lighter clutch lever. It just seems that no matter what I did, the problem always came back. Maybe it's due to my fantastic ability to clean the bronze plates each time :wink: . No signs could be found of tranny fluid leaking past the pushrod, so I don't believe that was causing the gradual degradation each time I got in there. If you assume that the plates needed to be replaced due to prior tranny oil contamination continuing to leach out of the porous bronze, then the cost of replacement bronze plates far exceeded what I paid for the Barnetts, and I was pretty confident the Barnetts would be up to the task (they are).

Brooking 850 said:
It has a 40 mm belt drive (therefore dry)...
The bronze plates will do the business given everything else is right!!
Note emphasis on dry! As Leadbeater pointed out so succinctly, adding oil takes a huge chunk out of their ability to transmit power. If you add "dry" to the list of "everything else is right", then, yes, they will work. I'm not yet ready to go that route. Besides, the Barnetts are working so-o-o nicely! No stiction, no grab at lock-up, very progressive action with the F-type, and no slippage when on the loud pedal. Just ask the Camaro owner who got a good look at my tail light this morning. Sorry; I couldn't resist after watching his prior antics through traffic...

I think we've beat this one to death. Thanks for all of your input and insight.

Nathan
 
Put on Dyno Dave clutch rod seal years ago.

Now I want to put the clutch rod seal on my Mercury. Attempts to contact Dave through Atlantic Green website email
address have been unfruitful (no response). Anyone know how to contact him or another source for the product?
 
lazyeye6 said:
Put on Dyno Dave clutch rod seal years ago.

Now I want to put the clutch rod seal on my Mercury. Attempts to contact Dave through Atlantic Green website email
address have been unfruitful (no response). Anyone know how to contact him or another source for the product?

PM'd you. :mrgreen:

http://nortonrally.com/inoa-rally-2015
 
Norton Solved their clutch slip issues on the rotaries. My Interpol 2 had 18 plates in it but then there was a good amount of torque to deal with.
 
Oh dear God when will Commando owners ever learn about Commando so called clutches...or vastly overweight unbalanced gearbox breaking flywheels as I refer to them!!
. For example if you fit a 50 tholu thicker pressure plate to make clutch lever action lighter ..which it will do ONLY if your diaphragm spring is set up CORRECTLY in the first place....then if it makes clutch lever action 20% lighter you are also reducing the amount of torque the clutch will transmit when fully engaged before slip occurs also by 20% making the clutch even more prone to slip problems and it takes a real brain to do that!!
The Commando clutch was DESIGNED as a DRY clutch and was NOT designed to be employed with oil on the friction interfaces.....Please take the time to learn from the web page..................................................
http://a20b767e.magix.net/#xl_xr_page_1
 
And can be redesigned for oil by simply changing to Barnett run-in-oil friction plates. Add Venhill cable then adjust stack until you have a one finger no slip, no drag clutch.
Also make sure to seal the pushrod somehow. The Dyno Dave seal works.
Many of us here have already done this and are blissfully unaware of the things you speak of, but still doing OK somehow.

Glen
 
worntorn said:
And can be redesigned for oil by simply changing to Barnett run-in-oil friction plates. Add Venhill cable then adjust stack until you have a one finger no slip, no drag clutch.
Also make sure to seal the pushrod somehow. The Dyno Dave seal works.
Many of us here have already done this and are blissfully unaware of the things you speak of, but still doing OK somehow.

Glen
I agree. Norton may have done the R back in the day but the end users have done the D over many decades as newer materials and processes have evolved. What is was in the day and what it is now is called evolution.
Ta.
 
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