Commando Clutch Stack Height
- Thread starter Howard
- Start date
At risk of diverting this to somewhere else, for which I apologise in advance, how do you "change the stack height" of a Commando clutch? I understand that the position of the diaphragm affect the pull on the cable but I wasnt aware that it could be adjusted.
There are different thickness outer plates available also fitting an extra plain plate may be possible.
I was told to set it with the spring dished in 1mm.
Chris.
I was told to set it with the spring dished in 1mm.
Chris.
Brilliant, thanks for that. I believe that there are some variations in the ramp shape of the lifter at the cable end which can make a difference also, I have a couple but am yet to get to the point of assembly. I have had some concerns about the lever lifting load of the Commando clutch. I recall in the 70's when several of my mates rode them that it was regarded as one of the worst features & they broke cables consistently. This is not unrelated to Vincents, I am about to build my Vincent Twin Comet F5+5AB/1/ with the Commando clutch & box attached. Roy
Yes there are two different ramps, dominator and commando, the dominator one ( distinguished by having two holes in it) is easier but gives slightly less lift. If you look on Norvil site it shows the dominator one. Make sure you fit as oil seal for the pushrod or you will have oil in the clutch all the time Norvil do a clutch nut with one in, I've just fitted one to my Norvin. The clutch still performed impecably but looked messy and flung rubber/oil/ali mix about.
Think about getting diagphram plated or powder coated on the outside to tidy it up unless you have it under a cover.
Chris.
Think about getting diagphram plated or powder coated on the outside to tidy it up unless you have it under a cover.
Chris.
Hi Howard, what was the prognosis on your clutch? Did a leaky rear main seal take it out or something else?
Kev
Kev
Hi Kev, apparently the plate was worn out, no sign of anything else. I'd have thought the previous owner was prone to slipping the clutch, but I've now got the log book and it appears to have had 5 owners in 21,000 miles so maybe they all slipped the clutch ???
H
H
Hi again Howard, when I changed the clutch on mine it was because of the rear main seal as I mentioned, the bike had about 95,000 Klms on it at the time, apart from the oil the clutch was in perfect nick, hardly worn at all.
The BMW that I sold with 350,000klm was still on original clutch and working perfect, I am surprised with yours.
5 owners in 21,000 miles? Maybe the clutch was not fully engaging or something
Kev
The BMW that I sold with 350,000klm was still on original clutch and working perfect, I am surprised with yours.
5 owners in 21,000 miles? Maybe the clutch was not fully engaging or something
Kev
All I had to do to get the stack height correct was to install a new set of Barnett kevlar linings.
Being a diaphragm type clutch, the Commanso clutch works differently than other multi plate clutches. As the clutch plates wear, the fingers on the diaphragm curl in and become extremely stiff to operate, As they curl in, the actual pressure exerted on the plates increases, so slippage is unlikely, but hard clutch pull is guaranteed.
OldBritts offers a group of surface ground plates to be used in getting the stack height correct. The purchaser receives half a dozen or so steel plates in varying thickness, uses whstever gives the correct height, then sends the extra back only to pay for those used.
The ideal height seem to be with the outer surface of the outer plate flush with the bottom of the circlip groove. This puts the diaphram in a flat position, so the fingers are very easy to work, as is the clutch lever.
Being a diaphragm type clutch, the Commanso clutch works differently than other multi plate clutches. As the clutch plates wear, the fingers on the diaphragm curl in and become extremely stiff to operate, As they curl in, the actual pressure exerted on the plates increases, so slippage is unlikely, but hard clutch pull is guaranteed.
OldBritts offers a group of surface ground plates to be used in getting the stack height correct. The purchaser receives half a dozen or so steel plates in varying thickness, uses whstever gives the correct height, then sends the extra back only to pay for those used.
The ideal height seem to be with the outer surface of the outer plate flush with the bottom of the circlip groove. This puts the diaphram in a flat position, so the fingers are very easy to work, as is the clutch lever.
Note that stack height referred to above includes the thickness of the diaphragm.
Dyno Dave, Or Dave Comeau, explains it better. He came up with the first clutch rod seal for the Commando and also does one for Dommies. Without the clutch seal my Dommie clutch would not hold, even when I switched to a Newby belt drive and dry clutch. Actually, ESPECIALLY when I switched to a Newby setup as the dry clutch would not tolerate even a spec of trans gear oil on the plates.
I have been told by those who have used both the Norvil cltuch rod seal and the Dyno Dsve seal, that the DynoDave seal is better, but I do not remember why.
Here is a link to DynoDaves article on the Commando clutch http.atlanticgreen.com/ndnsclutch.htm
Dyno Dave, Or Dave Comeau, explains it better. He came up with the first clutch rod seal for the Commando and also does one for Dommies. Without the clutch seal my Dommie clutch would not hold, even when I switched to a Newby belt drive and dry clutch. Actually, ESPECIALLY when I switched to a Newby setup as the dry clutch would not tolerate even a spec of trans gear oil on the plates.
I have been told by those who have used both the Norvil cltuch rod seal and the Dyno Dsve seal, that the DynoDave seal is better, but I do not remember why.
Here is a link to DynoDaves article on the Commando clutch http.atlanticgreen.com/ndnsclutch.htm