Topic: hydraulic clutch cb750?

[jaguar]

was looking at one for the bikes on the BOTY thread and saw a cb550 with a hydraulic clutch
did some searching and found that you can use a Magura XS650 set up on the CB750?
seems to show that i mounts under the cover and its out of sight.

anyone have more info on this?
pros and cons?
cost?
any one running one?

[Sam Green Racing]

CycleX do one Jag, I'll find a link for you.

Sam.

[Sam Green Racing]

Seems It's still in the development stage.

http://www.cyclexchange.net/index%20pics/Hydraulic%20Clutch%203.JPG

Sam.

[754]

 Fishead on here has built some clean-looking ones that use the tincover..

[Ricky_Racer]

Jag, do you have a link for the small Magura(?) slave cylinder that will fit underneath the stock clutch cover? I've been unsuccessful in my search. Thanks!  RR

[NitroHunter]

In the mid 80's I built a hydraulic clutch for my SOHC 750.
  Here's my "Hydra-Slide" dragster clutch story.   
  I machined a clutch cover to accept a hydraulic slave cylinder, as I remember it and the master cylinder were from an Interceptor (?). It stuck out of the side a little but looked pretty cool. The purpose was a simple drag start launch management system for a turbo bike, similar in concept to a fuel cars 'cannon' - Hydraulic controlling of throw out bearing movement. A flow control (needle / check) valve for engagement speed adjustment. Made a centrifugal flyweight clutch lock-up plate. 12v solenoid line lock activated by a microswitch at the throttle linkage. It actually was a rather simple setup - once all the machining was done. 2 semesters of Machine shop 'Independent study' at the local community college got it finished.
  Application at the track was another story.
  Barbecued not just 1 but 2 used clutch packs strait away. Tried adding counterweight but then lots of bogs. Pumped the turbo hard to make some boost, then got too much tire spin and crashed. So I quit and went Funnycar racing. 
 I still have that cover, adaptor, and lock-up, but no idea where the rest of that POS set up went to.

[jaguar]

http://www.fishheadbigbrakes.com/services.html

thats really the best pics that i can find.
info is scarce too


RR we seem to be playing Email/phone tag.....you around this weekend?

[fishhead]

  I've been getting a lot of emails on this.

I stopped making the hyd clutches because I ran out of the Magura units I was using and I haven't been able to find others, they have probably been discontinued. I originally had a box of them and when they ran out, I couldn't find others to continue offering the kits with. I found out that they were hard to find when I sold a XS650 Hyd clutch kit and had to remove the Magura unit of my CB750 to make the kit with. My CB 750 will get a larger slave cylinder that will stick through the "tin" cover.

  Magura has gone to the "Jack" units that basically replace the clutch cable (It looks like it would keep the stock adjuster, ball ramp,etc) and only replace the cable with a hyd unit. It seems like this approach would be easier and would require less fabrication/machining. The main differences between the different application "Jack" units would be the length of the "clutch cable" end and the length of the stroke. I don't know what application would be best for the hyd clutch assembly for the CB 750.

 Here's a "Jack" unit.

http://cgi.ebay.com/ebaymotors/MAGURA-HYDRAULIC-CLUTCH-KIT-DR-D-HOT-START-KITS-0120494-/220692093662?pt=Motorcycles_Parts_Accessories&hash=item3362461ade

Magura also uses mineral oil in their systems, often called Magura Blood. It is not compatible with any brake fluid and if you put brake fluid in the Magura stuff (labeled "Mineral Oil only"), it will destroy the seals and in turn destroy the Magura unit.

[754]

  Interesting..
 If you can get the seals for the other hyd unit we could build the unit again.. or use a more common kit, and build the rest..

[Ricky_Racer]

Thanks for the info, Dan. The slave cylinder you were using looked closest to a KTM application, but as you found, it seems to no longer be available. And the price of somewhat similar used KTM clutch cylinders is pretty high. Looks like the external mount (R1, Interceptor, Ducati, Yoyodyne, etc.) may be the most feasible/low-buck way to go.

Sure do like the hidden ones though....      RR

[a700guy]

Ktm has all but stopped using magura and gone to a brembo unit, better feel and uses brake fluid.....something to look into, look into a 250SX clutch unit and you should find it straight away.

[jaguar]

Is that a low profile set up?

[Ricky_Racer]

Is that a low profile set up?

Kinda, sorta... but I don't know if it has a bleed valve or not. There are a couple similar Magura types that do.    RR

[BLUE71TURBO]

Here's an aftermarket setup for a early kz1000.  Just to give ya an idea in what it looks like.  Hope it helps.   

     http://cgi.ebay.com/ebaymotors/Kawasaki-Z1-KZ900-KZ1000-Hydraulic-Clutch-Kit-/380134748525?pt=Motorcycles_Parts_Accessories&hash=item5881cbf16d

[DavePhipps]

PLease don't whack me over the head with something when I ask this. Why do this modification? There doesn't seem to much benefit from it.

[Ricky_Racer]

Because we can!    RR

[DavePhipps]

Because we can!    RR

That's a fine reason to do it, that I can totally agree with. Mods can be fun!
However, I'm still wondering if there is a benefit that I'm not aware of?

[bwaller]

One reason is that some of these big engines can use heavy clutch springs and the rider doesn't have to worry about carpal tunnel.

[Retro Rocket]

I have a Barnett clutch in mine and the extra lever pressure is the reason why i wanted to try this, everyone i have spoken too is trying to talk me out of doing it. I have an early gsxr 750 hydraulic set up and was going to look at converting that....

Mick

[DavePhipps]

I have a Barnett clutch in mine and the extra lever pressure is the reason why i wanted to try this, everyone i have spoken too is trying to talk me out of doing it. I have an early gsxr 750 hydraulic set up and was going to look at converting that....

Mick

Now that's a justification,, even though bwaller's response seemed a bit tounge in cheek.
From a personal experience the hydralic clutch on my old interceptor always felt vague, not enough feedback for my tastes.

[Retro Rocket]

The one on my GSXR1100 was good, light and easy to use....

Mick

[BLUE71TURBO]

I have a Barnett clutch in mine and the extra lever pressure is the reason why i wanted to try this, everyone i have spoken too is trying to talk me out of doing it. I have an early gsxr 750 hydraulic set up and was going to look at converting that....

Mick

                  What reason would these people try to talk you out of this conversion ?  If ya wan't to try something new and different
        I say go for it.  You might even make some $$$ out of your idea and labor.   

[Retro Rocket]

I have a Barnett clutch in mine and the extra lever pressure is the reason why i wanted to try this, everyone i have spoken too is trying to talk me out of doing it. I have an early gsxr 750 hydraulic set up and was going to look at converting that....

Mick

                  What reason would these people try to talk you out of this conversion ?  If ya wan't to try something new and different
        I say go for it.  You might even make some $$$ out of your idea and labor.   

I have been told that it isn't as reliable and lacks feel but my experiences tell me different......I'll look into it....

Mick

[turboguzzi]

got hydraulics both on my VFR and my GSXR, first one works almost as good as a cable, the later quite abrupt. Never having to lube a cable or having it breaking on you in the middle of nowhere are a plus

So getting better leverage is good in theory, in practice i doubt if you'll find a good range of MC's and slaves cyls to get the right ratio/feel.

In the other hand, the slave arm length and hence ratio on a cable setup can be easily changed, see here 

TG

[MidnightLamp]

I've seen it done on brit bikes where you run into the 'Why do I only have 1/64 inch of clutch travel for 1 inch of cable pull?!?' problem. A local guy used to run a VFR750 clutch cylinder on a unit BSA. It directly pushed on the clutch, and he was using a series of shims and spacers to get the throw just right. He seemed somewhat satisfied with it, but then switched to a powerstands setup and was very happy.

http://www.powerstands.com/acb/showdetl.cfm?&DID=43&Product_ID=198&CATID=17