RGS hydraulic clutch piston

H

harpmeister

Full member
Location
UK
Hi, I am looking for a 30mm hydraulic clutch piston for a RGS, could anyone point me to where I may be able to source one, I am UK based if that makes a difference.

Failing that could someone give me a suggestion on which material to use to make one and the depth of the hole from the outer edge that the ball bearing sits in

I have one but the ballbearing has been flattened and I cannot get it out of the piston.
 
If the only issue is the flattened ball bearing in the piston then I wouldn't bother about it. They all do that sir!
Of greater concern would be damage to the piston outer circumference which will lead to a damaged seal and leaking fluid.
I've used Wolfgang Haerter for this item in the past - email
 
have them in stock, I actually supply them to Wolfgang but we are in Aussie so bit of a distance to post to the UK
we machine our own pistons as we machine billet sprocket covers with hydraulic clutch set up for the 180 degree engines which use the same 30mm piston size
though there are a few 31mm original covers floating around
 
Hi if the ball bearing is stuck in the slave cylinder piston I think you will struggle to get it out without damaging the piston and or make the fitting of a replacement ball bearing difficult. If you have a pedestal drill or lathe you could try a small drill to break up the ball bearing but they are usually hardened so personally would not be confident.
In the UK I would suggest phoning the usually suspects
Keith Nairn
Ged
M Cox
to check whether they have one they would part with.
alternatively if you don't have a lathe and the know how, find a small jobbing engineering shop and ask them to make you one from your original part.

Bob
 
I believe they are aluminum, I can't say for certain but having had one seized in the cylinder the piston material was soft and easily marked when getting it out.

Bob
 
The piston is originally aluminium with that dark brown/grey anodising that Brembo use on their pistons (same as their master cylinders). I guess the anodising gives some surface hardness in case it wants to gall from the ally-on-ally, and better corrosion protection for the inevitable neglected maintenance and fluid full of water.
If making a new one what grade to use is a good question, but 6061 is a pretty versatile grade and anodises well. But again, you'll pay more for a 1-off anodising job than a new piston (my local place has a ~$100 minimum charge).
I doubt the damaged ball bearing would drill out, they're hard as a monkey's forehead. Would be salvageable by spark erosion I guess, but likely cheaper and easier to buy a new one.
 
I noticed that the ball on my RGS had worn flat and the end of the rod was 'dished', I made a small disc out of copper and wedged it above the ball and gave it a good coating of grease.
Still there after twenty years plus, been replaced a couple of times due to wear but seems to be doing the job.
 
The worn ball in the piston is of not great consequence. Keep it well lubed and all is good for quite some time. Disadvantage is a slightly higher amount of friction between ball and rod. Once the lube is gone, the piston can spin when clutch is deployed, this will quickly destroy the clutch cylinder/cover.

piet
 
Ralph Allen of Motalia Norfolk makes them in stainless, never bought one to try but no doubt will have to soon.

Installing a new cylinder in a cracked cover at pres for a UK pal, cicular crack, not very visible and a double crack (highly visible) either side of the bleeding bleed nipple, plus extended hose uonon for future proofing, I think he has lost the piston in the rebuild. I have genuine Brembo dust covers if you need them.
#CLEM
 
Hi Redax5 if its not to much trouble could you please tell me the depth of the recess that the 8mm ball bearing sits in and is stainless steel the best material to make one from

Thanks
 
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