Ducati Diavel Motorcycles Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter · #1 ·
I really love my XDS. I'm almost IN love with it. I'm not, however, too blinded by love to forget how smooth, easy, tender and sensual the clutch pull was on my 2018 Vulcan S. I also didn't forget the peppy, eager starter that went "Yalalala!" instead of the old man's "Ahem", "Ahem", "Oh well, I'll start" of the XDS. But that's another story. Let's focus on that heavy-weight lifter clutch pull for now.

So. After reading stuff on the interwebs, I concluded the solution to my problems would be one of 'em Oberon clutch slaves. I have been assured over and over that it will turn the pull from wrenching a joint out of an addict's hand into smoothing the curls on a virgin's forehead.

So. I went ahead and procured said item. It arrived together with 3 new screws, two copper seals and an extension I was made to understand I wouldn't need. I watched youtube videos on the replacement process and learned that it was very easy. Take the old one off, put the new one on, bleed, and relish the new softness.

So. Armed with the necessary tools and 500ml of brake fluid, I went ahead and did all the wrong things. Instead of taking the stock slave off, bolting the new one and only then transferring the banjo screw, I unscrewed the banjo, wrapped it in a towel and took my sweet time exchanging the cylinders. Needless to say, by the time I was ready to attach the banjo to the new slave, I had myself a towel soaked in brake fluid, an empty reservoir and, apparently, 8 gazillion cubic inches of air in the line.

So. In goes the fresh fluid, off goes the bleeding dust cap, on goes a tube that leads to a collection bottle. Clutch is pumped 6 times and held-in, valve is opened and closed, clutch is released, and repeat. And repeat. And repeat. And repeat...

3 hours later (I shit you not), I give up. Yes, bubbles do come out. Yes, the clutch goes from mooshy to less mooshy. Yes, fluid flows out of the reservoir into the collection bottle, and I keep filling it. I don't let it go empty so air can't get in.

3 hours. Let me tell you, it's not fun. There's brake fluid everywhere and my arms hurt. I'm also contemplating the nightmarish logistics of towing the bike to the dealer (I use it to commute to work every day) and being without it for who knows how long (parts need to come from Italy, which probably really means China, which is closed down due to the virus). Not fun!

Eventually, I give up. I determine the Oberon is a dud, or just the wrong part for my XDS. I take it off and put the stock clutch back on. This time I'm wise, though. I exchange the cylinders and only then transfer the banjo. Only a little bit of fluid on the floor, my hands and my face this time. Well, except for the part where you push the slave in and get a nice volcano of brake fluid all over your shiny fuel tank.

So. The stock slave is on, the reservoir is full, and I'm bleeding again. I'm bleeding the bloody thing for another 2 hours. The owls on the trees outside are looking at me funny. So does my wife. "You broke that beautiful thing?" she asks? "Why can't you leave things be?". Needless to say, that's very helpful. To her, that is. Not to me.

So. Funny things are happening. Sometimes there are bubbles, sometimes there are not. Sometimes the fluid moves, and sometimes it doesn't. I become desperate. I decide to "bleed the master cylinder". I'm not even sure if that's a thing on the XDS, but I do it anyway. Let me tell you. Big mistake. Fluid pours down (there is no bleeder nozzle on the master), and then nothing comes out even though the reservoir is full. "Aha!" I think to myself. "There is air trapped in the master, which I need to bleed out. This is why the darn thing didn't work for me. No one ever experienced that problem, which is why no one mentions anywhere on the interwebs... by I, the newcomer, have cleverly stumbled upon an issue that no one admitted before - or at least - solved before!". Well, let me tell you. You don't need to bleed the master. You certainly don't need to break the copper seal (especially if you don't have a new one) and get a nice leak going. Ignoring recommended torque (yes, completely horrible but I'm desperate at this point) I tightened the thing until my eyes bulged out, and the leak stopped.

So. I keep bleeding and bleeding. At some point I remove the custom clutch lever and put the stock one back, thinking that that might have something to do with it. Let me tell you - it doesn't. I connect a vacuum pump to the bleed valve and pump. I pump for 30 minutes while refilling the reservoir. There are bubbles, but the clutch is mooshier than ever.

So. I rewatch youtube videos, trying to figure out what I'm doing wrong. Nothing. There's one helpful fella who tells me "Bleeding the clutch isn't rocket science.". Well, let me tell you. If you get enough air into that system, it becomes fracking rocket science. I keep at it for another two hours, and the clutch starts to feel firm. I hold it in and try to move the bike, and it moves! Success! It is working! Happiness! Relief! The final test, of course, is to start the bike in neutral, pull the clutch and shift into 1st. I do that, and the bike immediately shuts off. Obviously, the clutch is not disengaging all the way and stalling the engine. So I keep bleeding for another 2 hours, repeating the test every 20 minutes or so. Let me tell you, there is nothing like realizing how utterly stupid you are for shifting into 1st while the kickstand is down and mistaking the shutoff to a clutch issue.

So. I'm 8 hours into it, and the engine now stays on when shifting into 1st (with the kickstand up, clever me). I fixed it! Yay! Let me tell you. It's quite a conundrum at this point, since I'm tired, covered with brake fluid and I have the bike exactly as it was 8 hours ago, with the stock cylinder on. So... do I, uh, install the Oberon and go through it all again? Hell yes! My mom didn't raise no wusses. I invite the wife into the garage, hand her the bottle of fluid and ask her to watch the reservoir like a hawk - never letting the level fall.

So. Like a practiced wizard, I switch the cylinders yet again. I'm so fast and nimble that only a few drops of fluid escape as I transfer the banjo over. The fluid doesn't even need to be topped off. And I bleed! Bubbles! Receding mooshiness! Success!

So. The Oberon is installed and the clutch works as prescribed. Neutral, engine on, pull in, shift into 1st (kickstand up, hardy har har). Works!

So. Let me tell you. It doesn't feel any different. The pull is the same, I can't feel jack sh*t of a change. Bottom line, don't replace your slave cylinder with an Oberon. And if you do, you'll be sad.
 

·
Registered
Joined
·
898 Posts


Just saw your thread and I felt like I needed to reply since I have the Oberon clutch cyclinder. And let me tell you I actually like mine, with the added PAZZO shorty levers it was like night and day difference. I can actually pull the clutch with just two fingers(index and middle with ease. I got mine done at a shop that works on Ducati's. I was quoted with 1 hour labour and change of clutch fluid. It's either you have a dud, you can go back where you bought yours from or you did the install incorrectly. BTW, the part number is on the clutch cyclinder. It's compatible on the Diavel as well
Also prior to searching around for a new clutch cylinder, Oberon actually had really great reviews from other bike owners online.

Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #3 ·


Just saw your thread and I felt like I needed to reply since I have the Oberon clutch cyclinder. And let me tell you I actually like mine, with the added PAZZO shorty levers it was like night and day difference. I can actually pull the clutch with just two fingers(index and middle with ease. I got mine done at a shop that works on Ducati's. I was quoted with 1 hour labour and change of clutch fluid. It's either you have a dud, you can go back where you bought yours from or you did the install incorrectly. BTW, the part number is on the clutch cyclinder. It's compatible on the Diavel as well
Also prior to searching around for a new clutch cylinder, Oberon actually had really great reviews from other bike owners online.

Sent from my iPhone using Tapatalk
Yes - I agree with everything you said. I have the exact same part (albeit in black). I read the great reviews and made the decision. My only issue is the result... I can pull the clutch with two fingers, but I could do that before, too. I don't think it can be installed incorrectly... it either works or it doesn't. I'll give it some time and see if it softens up. Thanks for commenting!
 

·
Registered
Joined
·
898 Posts
You are right, there is no way of installing it incorrectly. But what can go wrong is if you get air into the system that can cause issues. Also there was also an extra part that came with the Oberon clutch and you are not suppose to use when installing it. Only meant for older Ducati's. It will loosen overtime, maybe you should do the levers while your at it, lol. It's one thing after another ????

Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
869 Posts
I replaced my front brake fluid and spent nearly two days trying to bleed it. In the end I removed the short brake lever and pushed in the master cylinder actuating pin and hey presto a massive air bubble cam up into the reservoir. All was good after that.
my son called me some months later as he was having an issue trying to beheld his clutch on his Aprilia. Told him to remove his lever and do the same Again it then worked straight away, it appears that some after market levers do not have enough push to displace any trapped air in the master cylinders
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #6 ·
That might be it. No one tells you that in them youtube videos and articles. No one says "if you put air in, prepare to spend your weekend bleeding". Someone should warn people!
 

·
Registered
Joined
·
28 Posts
Never mind about the technicalities of whether this is a good upgrade or not, it is the most entertaining piece I've read in ages. Classic!!

Talhorns, you should try a home install of the Termi exhaust and tell us all about it...
 

·
Registered
Joined
·
33 Posts
I had an Oberon installed to replace my stock unit which gave up at 20k km and it's definitley an improvement for me. I do know the brembo master is less fun to bleed vs the magura on my KTM and you'd be better off pushing the fluid in at the bleeder and forceing the bubbles to the master. You're trying to force air down and the actual clutch line doesn't hold much fluid so even a little bit of air can scupper you. Is it two-finger light for me? No, I have felt lighter clutches on Multis with larger slave cylinders but I've heard they're even harder to find Neutral with so all a compromise.
 

·
Registered
Joined
·
10 Posts
Another trick is to use a zip tie, rope or whatever to keep the lever depressed overnight. Air wants to rise by it's nature in a fluid so keep the diaphragm "open" to let it rise.

Issues like this is why I only ever vacuum bleed with a mityvac and air compressor. The hand ones tend to be cheap and don't work as well.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #11 ·
Another trick is to use a zip tie, rope or whatever to keep the lever depressed overnight. Air wants to rise by it's nature in a fluid so keep the diaphragm "open" to let it rise.

Issues like this is why I only ever vacuum bleed with a mityvac and air compressor. The hand ones tend to be cheap and don't work as well.
I actually read somewhere that it is a bad idea to zip tie the clutch, since you put pressure on the plate springs overnight, which is bad for them. You should only zip tie the brake.
 

·
Registered
Joined
·
98 Posts
I had similar issues with bleeding mine and didn't realize there is a final step in bleeding in the reservoir - I also upgraded to shorty levers and the clutch pull is absolutely reduced and much easier. I'm sure if I would've stayed with full length levers it would be even more noticeable. Glad you finally got it sorted...trust me if you find my old posts on it, you can sense the same desperation in trying to resolve it.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #13 ·
I had similar issues with bleeding mine and didn't realize there is a final step in bleeding in the reservoir - I also upgraded to shorty levers and the clutch pull is absolutely reduced and much easier. I'm sure if I would've stayed with full length levers it would be even more noticeable. Glad you finally got it sorted...trust me if you find my old posts on it, you can sense the same desperation in trying to resolve it.
Thanks! For some reason I prefer the longer levers... but I guess I need to give shorties another look.
 

·
Registered
Joined
·
33 Posts
Have to say that the Master cyclinder blead is crucial as bubbles will rise over time. I finally did this and the Oberon is providing the performance that was promised... very smooth, lighter pull, easy to modulate AND no issues finding neutral.

If it's not done properly, it works fine when cold but as it heats up, the air expands and finding neutral is hard as the clutch isn't fully disengaging. I've seen a lot of feedback on 'hard to find' neutral which is one of the reasons the 30mm master cylinders might be a bridge too far. You get a super easy clucth pull but any tiny amount of air in the sytem reduces the already limit fluid capacity being stroked by the master and it becomes a PITA to find neutral at a stop.
 

·
Registered
Joined
·
98 Posts


Just saw your thread and I felt like I needed to reply since I have the Oberon clutch cyclinder. And let me tell you I actually like mine, with the added PAZZO shorty levers it was like night and day difference. I can actually pull the clutch with just two fingers(index and middle with ease. I got mine done at a shop that works on Ducati's. I was quoted with 1 hour labour and change of clutch fluid. It's either you have a dud, you can go back where you bought yours from or you did the install incorrectly. BTW, the part number is on the clutch cyclinder. It's compatible on the Diavel as well
Also prior to searching around for a new clutch cylinder, Oberon actually had really great reviews from other bike owners online.

Sent from my iPhone using Tapatalk
100% Agree, Same setup for me Oberon and Pazzo shorties, night and day difference.
 

·
Registered
Joined
·
5 Posts
I'd love to know if anyone has measured the bore diameter of the Oberon v the factory Slave.

Physics being what it is...if the cylinders are of the same diameter it is absolutely impossible for there to be any mechanical advantage over the factory slave.

If the Oberon has a larger bore then indeed the clutch pull will be lighter with the included longer stroke of the master cylinder required to gain the same slave travel and corresponding clutch disengagement.

The other factor which can influence perception of feel....If the Oberon is using a low drag piston seal with less stiction the initial pull will be easier while not actually lighter.

OEM is attempting to get the lightest clutch pull force while having an acceptable travel of the clutch leaver... Always a trade off!

My partner rides an HD Sportster which only come with a mechanical cable clutch....I designed and manufactured a direct acting hydraulic clutch assembly which by pure mathematical means, reduced the actual lever pull force by 40% over the mechanical actuator as measured with a force gauge attached to the clutch lever.

Also greatly reduced the lever travel required over the mechanical ramp and ball of the OEM.... the same cannot be said when modifying an already hydraulic system....less lever force= longer lever travel and vice versa.

P.S.....Gotta agree with Robbo... classic story telling!! LOL
 

Attachments

·
Registered
Joined
·
98 Posts
I'd love to know if anyone has measured the bore diameter of the Oberon v the factory Slave.

Physics being what it is...if the cylinders are of the same diameter it is absolutely impossible for there to be any mechanical advantage over the factory slave.

If the Oberon has a larger bore then indeed the clutch pull will be lighter with the included longer stroke of the master cylinder required to gain the same slave travel and corresponding clutch disengagement.

The other factor which can influence perception of feel....If the Oberon is using a low drag piston seal with less stiction the initial pull will be easier while not actually lighter.

OEM is attempting to get the lightest clutch pull force while having an acceptable travel of the clutch leaver... Always a trade off!

My partner rides an HD Sportster which only come with a mechanical cable clutch....I designed and manufactured a direct acting hydraulic clutch assembly which by pure mathematical means, reduced the actual lever pull force by 40% over the mechanical actuator as measured with a force gauge attached to the clutch lever.

Also greatly reduced the lever travel required over the mechanical ramp and ball of the OEM.... the same cannot be said when modifying an already hydraulic system....less lever force= longer lever travel and vice versa.

P.S.....Gotta agree with Robbo... classic story telling!! LOL
If I recall it was a 2-3mm difference - definitely noticeable clutch pull difference.
 
1 - 17 of 17 Posts
Top