Dry clutch conversion

Ok, so here we go. I'm committing to this.

You may ask "but why?". The 3 biggest reasons for me, 1- emotional, 2- why not and 3- THAT SOUND!!.

What I have learned so far, this is a pretty easy job for the 13-14 bikes. They share the same internal design as the 1098, 1198. Streetfighter, 999, 748.....basically the last generation of motors. The 13-14 use a separate bolt on oil pump assembly where the 15+ bikes have the oil pump cast n machined into the case itsself(notice differences in schematic pics).

This can be done on the 15+ bikes but need the clutch oil tube modified to clear the bigger 'knuckle' on the oil pump(the clutch cover comes in contact with that point of the oil pump).

My bike is a 13 so its 'Thundercats GOOOO!' for me. I mocked up the dry clutch cover and gears and it is all lining up perfectly. You need both primary clutch gear and secondary gears to make this work(I'm not sure about needing an oil pump gear off the 999 motor yet because the dry clutch gears mesh up perfectly in mock up).

I currently do not have a clutch for this conversion yet, I intend on getting the Kbike slipper but might juts grab a used clutch for really cheap just to get it going.

You may notice that the oil site glass is in a different location to the OEM hypermotard piece. It looks like they are parallel with eachother and the ground. I will watch the window as I fill it up and take note of what it takes.

This all started because my OEM pressure plate cracked. I reached it with a billet Ducabike pressure plate. So far it is holding up but during mock up of the dry system I installed stiffer Barnett springs and expect that the Ducabike plate will fracture too. I also have the judder spring kit. I installed it a couple years back and it made the OEM clutch more predictable and live-able in daily life(this is my daily driver). . I converted to hydraulic clutch actuation. I also have a rapidbike quickshifter. I installed the stiffer springs because it feels like it is slipping while hammering the quickshifter. Now, to break it all down, the slipper assembly was engineered to work with OEM springs and without the judder spring. I believe that judder spring (along with age, I have 17k miles on the bike) created the slipping. Adding the stiffer springs should help eliminate slipping but now the slipper springs are impacted by the change. I believe it to be a tension balance between the springs.

This is what I have learned so far. I will continue to update as I progress.

Notice the wear on the ducabike pressure plate. There is only about 2k miles on it.
Notice the differences in Barnett spring and OEM. Its subtle but they are slightly thicker(and only like $25).
Notice the fractured OEM plate. 2 of the spring pockets are fractured at the end and around the cup

I also did the factorypro detent shift mod about 2k miles ago. It requires more force to shift bit it definitely locks into gear with every shift. It has a stiffer spring, smaller roller and ceramic bearing. It almost eliminates all false neutrals. Although, while being lazy shifting I have hit a false neutral between 5th n 6th a couple times still.

BadToTheBown said:

Is the Ducabike Pressure Plate cast or billet?

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Appears to be billet to me. The whole thing is covered in machining marks. Not that it coukdnt have been cast then machined but I think its billet.

BadToTheBown said:

Looks like Ducati is following your lead for 2020 950 Motard...

Click to expand...

It would be cool if it were an option from the factory. Almost all the parts are here. As soon as the new clutch plates get here I will be able to move forward.

Everything is dry fit(minus the primary gear) for my dry clutch conversion. The clutch is a kbike slipper. The output shaft on the 821/939 is shorter than a normal dry clutch bike so the hub of the new clutch needed to be turned on the lathe to accept the make shaped nut that recesses back into the hub(every kit comes with the hub machined and a special sealing nut) That nut I'm using comes from the 1100 hyper as well as a few other bikes. One thing that messed me up 2 times now, in all the kits you see on line(the 3 kits that are available) show a splined primary gear. The 821/939 has a tapered fit keyway retainer gear. This needs to be taken from the 916 or 1100 monster/hyper. The 1100 hyper EVO clutch gear is drilled to make it lighter. It drops the weight by a half of a pound. If you are doing this pay attention to the primary gear, the 821 and 939 are NOT splined.

The next big obstacle (or so in was thinking it would be). How to seal the clutch pushrod within the output shaft/clutch hub shaft. All the kits use a super fancy special nut that recesses into the clutch hub. The nut also retains a seal in the end of the nut. Come to find out, part number 93040491a is a seal, part number 70250441s is needle bearing and 96855009b is a shim tube that the seal and bearing press into then the whole assembly presses into the output shaft/clutch hub shaft. That supports the pushrod on the clutch side and seals the pushrod(normally oil flows through here to lubricate the wet clutch. We are switching to dry so this needs to be blocked or else it will dump oil out the middle of the clutch). This bearing, seal and shim is a very snug fit. I'm confident with its hiding and sealing abilities.

The kbike slipper clutch I got requires a beveled nut that allows the center spider diaphragm spring to flex,. It has a shoulder that doesnt clamp it ruggedly to the hub. The clutch comes with 2 nuts(some bikes use a smaller threaded nut. I was able to take one of the nuts to the lathe and turn it into a washer/spacer which will hold and allow the spring to flex as intended. This was a big relief to me. I was thinking I would need to make a crazy fancy sealing shoulder nut as supplied in the kits. As it seems right now, all the stressful pieces are worked out.

Next obstacles, I needed to switch to the longer push rod. Luckily when I switched to the hydraulic pushrod system I ordered all 3 lengths made(all used. Only ~$10ea. I'll give an actual length when I finish assembly).

One thing to note, I needed to go to the local bolt supplier to get new bolts for the dry clutch cover, the wet clutch cover bolts have a flair at the base that doesnt allow them to fit into the recesses in the cover. $8 for all allen head bolts with locking washers grade 8.

I am set on running that lightened clutch gear. I have ordered 3 sets now. 1 from a streetfighter(lightened clutch gear but splined primary gear 59 tooth $ 32 tooth)one from a monster s4r (solid clutch gear 59 tooth and 32 tooth splined) and now the new one that is on their way here, from a st4/916 (solid clutch 59 tooth and TAPERED 32 tooth. I'm hoping to use the 59 tooth streetfighter clutch gear with the 916 primary gear). The best way to go about this would be to find a 1100 EVO motor clutch gear and primary gear set but it's rare to find.

Anyways, that's where I'm stuck till the new gear gets here, a week from wednesday. You may ask "why do this". For me it is for emotional reasons. I have always wanted a ducati with a dry clutch. Also, this is a hooligan bike. Dry clutch SCREAMS hooligan. The next question is usually "why not just buy a kit". The kits range from $2400-4000. I will have less than $1000 into this including all my trial and error. I intend on putting a full parts list together of what is needed once I'm done.

I have a bunch of other pics but it is saying they are too large to upload even though I tried screen shotting and resizing but no success. I'll upload more as I am able too

I just finished the conversion earlier this week. Temps have been in the 30s so I havnt ridden much but I have been out. First impression, the feel is very consistent. It isn't as on/off as I have read in some forums. I'm very happy so far. I will do some better coverage on the finishing of this project soon. I'm trying to upload a few pics but every single pic is saying it's too large even with cutting and cropping. I'll need to figure out how to resolve this so I can share the pics.

Ok. So in the end, I had to make a male nut with a beveled area to allow the spider spring to work while still retaining the hub. The output shaft on the wet bikes is shorter than the shafts on the dry bikes so the hub needed to be machined to receive the shoulder of the nut. That tolerance I made very tight to allow the shoulder of the nut to help support the hub itsself. I'm very happy with the outcome here but it would have been far easier to modify a non-slipper clutch or even the kbike adjustable slipper clutch(it uses secondary springs in place of the spider spring. I will eventually upgrade to the adjustable. It only costs ~$120 and will drop right in to my modified hub).

There was a little concern for the output shaft that the basket gear and clutch hub rides on. Their is a oil port that exits under one of the gear bearings. The issue is that their is no flat surface for an o ring to seal that point so I was expecting there to be a little leaking. During assembly I used some 3M flange sealant at that location. Its ment for situations like this and so far so good.

Next issue, primary and basket gears. I spent the most time researching this. Most people who are selling these gears aren't using the pics of their actual parts so the hours I spent counting teeth and deciphering taper vs splined arrangements were all for nothing. Orderd from various Ebay sellers as well as Gotham. Gotham's response 'woops, we posted the wrong pic. The part number is correct so we dont really care. You can keep the gears, want a refund?' Which is good that I got my money back but was another 2 weeks wasted. They since have changed their pics. This isnt a problem if you swap the gear set along with the oil pump front the donor bike but the other oil pump spins at a completely different rate than the oem pump in our bikes. I was told that it wouldn't be an issue but I fought to keep my OEM pump and ratio. The issue is, the primary gear MUST be a taper fit(every kit you see shows a splined fit) and the oil pump gear on that primary gear MUST be 25 tooth. After ordering 5 sets of gears I finally got a Ebay seller that wanted to make my situation work so he went through his inventory and found a set that has 25tooth oil pump. It came from a DS motor. Now, if you are obsessive like me you you want to get the lightest rotating mass possible. Many gear sets will work as long as the primary is tapered and has a 25t oil pump(unless you want to swap oil pump...which can only be done on the 13-14 bikes. 15+ has oil pump machined into the engine case) but an easy rule of thumb, the 1100 monster gears will work as will the 1100 evo hyper gears. BUT!!! The hyper 1100 evo gears are lighter by over half a pound.

The other issue, oil flow through the output shaft. That needs to be stopped. Their is a pushrod that actuated the clutch that gos through this shaft along with oil flow. That oil flow was ment to lubricate the wet clutch. It dumps out the end into the center of the clutch and flings the oil out ward. It also lubricates a couple needle bearings that the trans gears ride on. There are 2 methods to do this(or so I thought). 1, buy the needle bolt from ducati Omaha that gos behind the front sprocket on the left side of the motor. That plugs the oil passage and now that shaft runs dry(from what I can determine). I didn't want to do this but I'm prepared to do it if I have too. 2, make a super fancy nut that holds the clutch hub on and seals the pushrod. Kbike and someone else uses this method but they WILL NOT sell one separately from their kit, believe me I tried many times and many different ways. Now, the 3rd way. There is a needle bearing and a tiny seal on many of the dry clutch bikes inside that shaft. Their is also a sealing/shim sleeve that the bearing and seal fit into perfectly. All of this is OEM parts available through ducati Omaha. I pushed the seal into the sleeve then the bearing into the sleeve then pressed the whole assembly into the output shaft. It is a very snug fit but its intended to be a snug fit.
While I had this all apart I decided to micro polish the gear tooth faces. That is said to make for a better/smoother delivery.

After months of sorting out gears I was finally ready for assembly. Notice in the pics, complete gear set with clutch vs complete gear set with clutch weight. The dry clutch will be ADDING 1lb to the rotating assembly(I machined down my flywheel to make up for this a little bit. I cut a little over half a pound off of the flywheel so in total I am up a little less than half of a pound).

Anyway, so far so good. I will put together a list at some point and upload it here along with part numbers and prices I paid. I'm into it for quite a bit less than $1000 including the extra parts I ordered and wrong parts I paid for.