Im contemplating fitting an Oberon clutch slave cylinder to my 1098 Streetfighter because of air getting into the line, affecting engaging neutral within a few days of bleeding (many reports that the Oberon performs more reliably). Can anyone tell me what the standard Ducati slave cylinder piston diameter is on this bike, because I am a little concerned about reduced travel with the 29mm Oberon piston? Thanks
Thanks Chris but something doesn’t make sense to me. Within a few days of bleeding, the end of my clutch lever is moving 20mm before it loads up (10mm after bleeding) and I then have difficulty engaging neutral. Total movement before it hits the bar is 75mm, so 15% reduction in travel is enough to cause problem. The Oberon has 29mm piston, the Ducati 25mm ref the table, so 35% reduction of movement! And yet many people report that the Oberon is fine. Seems like I’m missing something....
It’s not as simple as push rod length is it? There were two lengths and I used to be able to quote them, difference between them is about 10 mm… From new, the Oberon kit comes with a small “slug “of steel to make up the difference should it be needed . The longer length was used in later bikes but I’ve been caught out before when someone has used the shorter push rod in a later engine.
I've put an Oberon on my Multi Enduro. Definitely a lighter feel to it, can't say whether it has less 'throw' at the lever end.
Thanks guys, I’ll take some measurements and mull this over. Might strip the clutch plates out and check for warping etc....
The short pushrod was only fitted to earlier bikes with the single phase alternator. From about 1998 onwards all Ducatis had the 3-phase alternator with different crankcases and the longer pushrod. With a push rod that is 10mm too short the lever will come to bars with no clutch action whatsoever. Have you tried bleeding it at the master cylinder? Any tiny bubbles in the line will accumulate and end up at the master cylinder banjo after a few days.
But short pushrod can’t be ruled out 100%, I never found out whether it was a parts bin special or whether components had been retrofitted, but have found the difference in the pressure plate centre spigot on post ‘98 bikes. EDIT:- later pushrod = 335 mm long mm, earlier pushrod = 325 mm long, so easy to rule out now.
In 1999-2000 Ducati updated the slave cylinder design to lessen/ eliminate the piston sealing/ seizing issues, and the redesign needed an extra 10mm on the rod end of the housing to achieve, hence the +10mm. These updated slaves are usually notable for the visible large 'end-plug' where the pistons & seals are inserted during assembly, whereas the early style loaded the piston assy. from the rod-side. I swapped my leaking original '98 slave & rod with a set from a 2004 and it works a charm. That pressure plate 'spigot' should be the same between all dry-clutch era years according to the parts manuals. I have heard of some of those aftermarket slave adapter extensions being installed on the pressure plate side instead of the slave side though, so...
^Not sure what this post means, previous post wasn’t questioning design origins, just trying to help with the actual lengths and the period when each length was fitted..
Same here, not knowing about this 20+ years ago and buying a new slave that needed the slug ( but didt come with one) , and no forum to ask, I seem to recall inserting a short nut and bolt...
On my Multi 1200 switching to an oberon slave just exacerbated the air problem and I had trouble engaging neutral earlier than without. So if it's not the slave at fault you may find it get's worse before you replace the part that makes it better. I think you will also have a 15mm master but check for numbers on it like shown here between the banjo and the handlebar clamp When I brought mine it came with an extender for the push rod but it wasn't needed. Here's the chart with the Oberon included, as you can see it's one of the combinations at risk of bad
I answered the rod length concernin that oberon supply their slaves with it, gave a newer version of the chart you are (observe the presence of Oberon) using and said how to check the piston size on the clutch master, what do you feel I've missed. It's not like you helpfully told OP the Oberon was a 29mm slave when posting that chart.
