Clutch slave size?

Mr Gazza · Yesterday, 07:10 PM

Please could anyone tell me the diameter of a standard clutch slave piston?
I'm after the size of the external type that bolts on the left side alternator cover.

I'm asking for a very good friend who is looking to make his wife's M600 clutch lever a lot lighter to help with her arthritis.
The 600 is an early one with the internal clutch side slave.
So being a very competent engineer, he is looking into boring the cylinder out and making another piston.
He did a series of experimental slaves for my Commando and they all worked well on a test rig, so he knows what he's doing.

If I knew what the standard size for the other side is I could compare that to the aftermarket ones to give him a guide size to aim for. Standard on the internal slaves is 26mm. I've got a feeling the external ones are too?

So far I have 29mm for Oberon and 27-27.5-28.5 and 30.5 for Elovuzione slaves.
If anyone knows what Factory Racing and others are it could be useful.

Thanks in advance.

Darren69 · Yesterday, 07:27 PM

There's a chart in this thread:
https://www.ducatiforum.co.uk/thread...iameter.75486/

Mr Gazza · Yesterday, 08:04 PM

Thank you Darren, that's absolutely perfect.

I found it on our very own forum a few minutes earlier and have already sent it to my mate.
It was originally compiled for Avanti Race Parts by Larry Shazaam Kelly apparently.
Name sounds familiar, but...

stopintime · Yesterday, 10:51 PM

Wet clutch on my 800 (maybe on that 600 too?) is the very standard 26 mm. I replaced it with a Yoyodyne 29 mm and that's just about what it can handle. Maybe 30 is ok too. I need the whole range of the lever to go from fully engaged to fully released (no drag).

Just a small real life observation.

Yesterday, 07:10 PM	#1
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,963	Clutch slave size? Please could anyone tell me the diameter of a standard clutch slave piston? I'm after the size of the external type that bolts on the left side alternator cover. I'm asking for a very good friend who is looking to make his wife's M600 clutch lever a lot lighter to help with her arthritis. The 600 is an early one with the internal clutch side slave. So being a very competent engineer, he is looking into boring the cylinder out and making another piston. He did a series of experimental slaves for my Commando and they all worked well on a test rig, so he knows what he's doing. If I knew what the standard size for the other side is I could compare that to the aftermarket ones to give him a guide size to aim for. Standard on the internal slaves is 26mm. I've got a feeling the external ones are too? So far I have 29mm for Oberon and 27-27.5-28.5 and 30.5 for Elovuzione slaves. If anyone knows what Factory Racing and others are it could be useful. Thanks in advance. __________________

Yesterday, 07:27 PM	#2
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,091	There's a chart in this thread: https://www.ducatiforum.co.uk/thread...iameter.75486/ __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

Yesterday, 08:04 PM	#3
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,963	Thank you Darren, that's absolutely perfect. I found it on our very own forum a few minutes earlier and have already sent it to my mate. It was originally compiled for Avanti Race Parts by Larry Shazaam Kelly apparently. Name sounds familiar, but... __________________

Yesterday, 10:51 PM	#4
stopintime Registered User Join Date: Dec 2010 Location: Oslo Bike: S2r Posts: 448	Wet clutch on my 800 (maybe on that 600 too?) is the very standard 26 mm. I replaced it with a Yoyodyne 29 mm and that's just about what it can handle. Maybe 30 is ok too. I need the whole range of the lever to go from fully engaged to fully released (no drag). Just a small real life observation.