Hydraulic clutch conversion part #s

I'm looking to do the hydraulic clutch conversion that people have done using the Magura master and slave cylinders. I haven't seen that type of slave cylinder for sale anywhere. I know that Magura makes it, but I really can't find any info on it. Does anyone know the part number or the model it is designed for?
Also, as far as the master cylinder goes, I'd like to hear from someone who has done the conversion and is happy with how it performs as to what size bore they used. Different bore sizes will yield differences in lever effort and travel of the slave cylinder, so there should be one size that is the best compromise between easy lever effort and enough slave travel to completely disengage the clutch and reduce the drag that the XS650 is known to have. Thanks.

Welcome to the site!

Is the magura slave that you are talking about the one that connects to a short cable to pull the worm gear? If so, that's probably not the route you want to go because the worm gear is part of the problem.. Every hydro clutch conversion I've seen (including mine) use a slave cylinder that pushes the push rod directly. Well almost directly... you'll still need a short rod to get from the slave to the pushrod. I've seen a few that use Honda VFR750 (I think) slaves, or other early 80's honda slaves. I bought one that was a 38mm bore and I needed to use a 5/8" or 16mm master to push it. It worked okay. I didn't test is much.

I have a 12.9mm clutch master that matches the brake side that I'd like to use so I searched the net high and low to find a smaller slave (that was cheap). Ended up getting one from an older Kawasaki that was about 33mm. Ideally I'd like one smaller but then you're talking custom parts for Ducati's. Some Monsters came stock with 25mm slaves (if I remember correctly) that tend to leak, and people swap them out for larger ones to make the pull easier, and to stop the leaks. So a lot of companies make 26-30mm slaves but they cost about $200.

When I was looking for a new slave, I created a simple excel table showing master cylinders sizes relative to slave cylinder sizes where if you determine the push of the master, it will show you how far the slave will move. I was shooting for 2.5-3mm of pressure plate movement. I'm not sure where I found that number but I can't find much to support it. I'll try to find that table...

- common conversion GP-GPZ


- or make one


- these EVO1 radial pumps from performance technology look interesting

If you go over to the 650 Rider archive (650rider.com) and type in 'hydraulic clutch', you'll get a bunch of hits, including this one:

http://www.650rider.com/index.php?name=Forums&file=viewtopic&p=7134#7134

I plan to do this mod on my 78E cafe project.

Here's another one. http://www.650rider.com/index.php?name=Forums&file=viewtopic&t=5320

It's pretty much that same process that I did except I used a friend's mini mill and modified one side cover for a 38mm 3-bolt slave, and did another for a 33mm 2-bolt slave.

Thanks for the good info and links. I considered using one of the kits that pulls on the existing release mechanism, but I quickly wrote off that idea for the reason Travis listed.
Travis, were you able to compare the 38mm slave to the 33mm unit? I'd be interested in which unit worked better.

I haven't finished the side cover for the 33mm one yet, but the idea was that I would match the 38mm slave with the 16mm master cylinder or match the 33mm slave with the 12.9mm master. I decided to change to the 33/12.9 setup because the 12.9 clutch master matches my brake master. On paper, the 16/38 setup should provide for a little bit more clutch separation at the expense of more pressure needed. In general, I'd say any hydraulic setup you go with (that provides enough pressure plate movement) will be pretty easy on the hand.... but some of that depends on how stiff your clutch springs are, how far you want to push the pressure plate, and the leverage provided by the master cylinder lever to the master cylinder piston.

how much does that run and is there any where i can send my parts to have it done

floydward13, welcome to the site.

Slave cylinders can be found new or used. Plan on spending $30-$200 for that. Same goes for the master cylinder.

If you can't modify the engine cover yourself, you'll have to find someone who can. Blacksmithbilly mentioned years ago on the JockeyJournal that he would do machine work on the side cover. He's a member here too but hasn't been on in a few months. http://www.xs650.com/forum/member.php?u=2569

You can have a custom hydraulic line made for about $50

So you could do this for about $100 on the low side or maybe up to $500 on the high side with new parts and sending out your side cover for machine work.

So I dug up that spreadsheet I made and cleaned it up a little bit. It isn't perfect but should get the point across. If anyone notices any major errors, let me know.

I did some measuring on my clutch. I found that with stock springs you get coil bind at about 4 to 4.5 mm of pressure plate travel. The stock lever, cable and actuator move the pressure plate about 3 mm. Increasing the plate travel to about 3.75 to 4 mm to be about max.

Leo, great information! Thank you. Looks like I may have swap out some more parts.

One thing I forgot. With out any springs the pressure plsate moves about 5mm maybe a bit more. This is where it hits the side cover.

It's all Greek to me, but I would like to match my brake master. Would this master http://www.jpcycles.com/product/4300378 (Harley replacement with 11\16" bore) work with this slave(have no idea what it is)?