Oberon clutch slave fitment

Originally Posted by rollo22

Nick
Have you been fiddling with the lever end ? and thus resulting in the master cylinder not moving back far enough to release the fluid back into the pot.

When putting the Oberon one on try without the clutch line connected and see ifit seats correctly. beware of fluid squirt.

It's not related to the lever end, because the hydraulic pipe is currently unattached from the slave and the system is empty of fluid!

Before I embark on cutting the push-rod down, can anyone advise on which end goes where? One has twin O-rings, the other doesn't. My ST4 workshop manual doesn't show the details but I may be able to find them in the parts list.

Nick

[Mr Gazza]

The O-rings go to the slave end.

[Luddite]

Originally Posted by The Clockie

Before I embark on cutting the push-rod down, can anyone advise on which end goes where? One has twin O-rings, the other doesn't. My ST4 workshop manual doesn't show the details but I may be able to find them in the parts list.

Nick

The twin o-rings are at the slave cylinder end.

Edit:You beat me to it, Mr Gazza!

Thanks Chaps. That the O-rings go at the slave end was indeed shown in the parts list pics on the clutch section of the forum. I'd better check everything is round the right way before I take a cut-off disc to the rod! I can't see any alternative at the moment, apart from buying a new old-style push-rod.

Reading the old threads here, it appears all were mystified by the persistent blackening of the clutch fluid. As I mentioned above, it was the use of NBR rubber in the seals wot dunnit. Even an aftermarket slave from Vee-Two in Oz went the same way but they then upgraded to Viton seals and the problem disappeared.

Nick, getting there slowly...

OK, the mystery about the incompatibility of the Oberon slave with my S4R is solved, thankfully before I started hacking the original push-rod down.

The makers suggested I measure the depth and throw of the cylinder, and I compared it with the original Ducati one that does fit and the dimensions were virtually identical. Bemused, I tried it one more time with the clutch fully assembled and realised that the Oberon wasn't seating on the case because the body was fouling the chain. And the reason for that was that whoever assembled it left the screw-in plug on the inner face in the wrong position so the cutaway that should give clearance for the chain didn't do so. What a relief: if I'd gone ahead with shortening the push-rod, it wouldn't have made any difference at all!

When Oberon saw the photo of old and new slaves, they immediately put a new replacement in the post. Steve Street, the director, is a very responsive chap and I commend him and his products, but someone should get a kick up the bum...

Nick

[Mr Gazza]

I must admit to a secret little sharp intake of breath when you said you had decided to chop the rod. I'm pleased that you got to the bottom of it before the unkind cut..

I wouldn't mind a chat with this Steve chappie to see if he can supply seals for my Oberon that will keep the fluid clear.

[Flip]

Yes it would be interesting to know when they changed the seal material as my Oberon slave cylinder has always turned the fluid black too- although to be honest I've never been bothered as my bike has the coffin reservoirs so you can't really see it and it doesn't seem to affect the operation of the clutch.

I only really fitted it as it matches the other gold anodised bits on my bike, I don't think it has made an awful lot of difference to the lever pull but I've also never thought the Monster clutch particularly heavy anyway.

It's kind of mid-way with both my little race bike and Vespa P200e's clutches being heavier while my Yammy Thundercat is (a lot) lighter.

Angling the lever(s) so they keep your hands/wrists in line with your forearm makes a bigger difference to ease of use and rider comfort in my opinion.

[rollo22]

Originally Posted by Mr Gazza

I must admit to a secret little sharp intake of breath when you said you had decided to chop the rod. I'm pleased that you got to the bottom of it before the unkind cut..

I wouldn't mind a chat with this Steve chappie to see if he can supply seals for my Oberon that will keep the fluid clear.

I was told by a Ducati chap that the black clutch fluid is caused by the rubber seal cap in the reservoir

I changed mine to the clear ones as used on new monster and no black fluid

[Darren69]

Originally Posted by rollo22

I was told by a Ducati chap that the black clutch fluid is caused by the rubber seal cap in the reservoir

I changed mine to the clear ones as used on new monster and no black fluid

That might be partly true but its more likely to be the slave seals otherwise wouldn't the brake fluid would turn black too?

I'd still be interested to find out more about these clear reservoir seals you mention.

[Mr Gazza]

Originally Posted by rollo22

I was told by a Ducati chap that the black clutch fluid is caused by the rubber seal cap in the reservoir

I changed mine to the clear ones as used on new monster and no black fluid

By which I assume we are talking about the black "rubber" diaphram in the top of the pot? I have the standard round first generation remote pots on mine with custom caps but the original black seal/diaphragms.
I know the pots are of different design, with the brake having two screws in the cap, while the clutch is a screw on cap, so I suppose it's possible that the diaphragms are different materials, otherwise both pots would be affected, as Darren said.. Seems odd though?
The clutch diaphram is much more visible than the brake and produces a flash of black in the translucent pot even if the fluid is clear, so a clear diaphram would help in that respect at least.

I will enquire at Moto Rapido for availability of a clear seal and if I can get one it will part of the pre Weekender service.. My money's on the slave seals though.

Anorak note.. Interesting word; diaphram. It gains a "g" in the plural; diaphragms.