Hydraulic Clutch Rod Clearance?

TheMonkey

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I bought a project bike, history unknown, it has been sitting for years. I rebuilt nearly everything but I did not go into lower crankcase or take off right side cover. Oil I used is 20/50 Valvoline ‘racing oil’ (full dose of zinc)

I milled the left cover and put a VTR1000 clutch slave on.

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The pushrod is a 304 SS 8mm rod to replace the single rod I pulled out from under left cover. I cut the length with zero clearance. This means slave fully bottomed out, the new rod length was set to that point. I figured after sitting so long, it needed some Kentucky windage... thought some crud and old surface would knock off clutch creating some clearance after first runs. If I understand correctly, as clutch wears, the ‘resting position’ of the slave creeps further out from bottom?

Clutch worked great at install. Lever feels perfect. 38mm slave, 14mm master.

It did take effort to break the old clutch loose while in gear and rolling the bike to/fro with lever in.

First shakedown run today on my project huge smile... everything was awesome. Buuuut...

As I went through break-in process to seat the rings, the bike got fully warm and the clutch was getting plenty of use. Lever started feeling mushy and clutch started slipping as my break-in throttling started opening up more and bike got fully up to temp.

I believe clutch slipping was heat induced, rather than more throttle because even part throttle started having problems.

As the ride settled and bike cooled, the lever felt good again.

Parked it. Here I am.

I know the hydraulics in slave can expand with heat, but sorta seems like it should still bottom out and just expand up into reservoir. Does the clutch pack expand with heat (pushing rod against bottom of slave)?

Feels like I should shorten some clearance in rod. Suggestion on how much?

Also, seems like I should drain oil and pull right side cover for inspection of clutch pack condition and measure slave throw. My first XS... advice on what to look for or how to measure?

Thanks. Hopefully that’s enough info.
 

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A good thread to read.

http://www.xs650.com/threads/hydraulic-clutch-intrest.48726/

If/when the clutch plates wear down (thinner), the pressure plate settles in deeper, to the left, requiring a shorter pushrod.

As the engine heats up, the engine expands, pushing the clutch hub (including clutch plates and pressure plate) to the right. Producing pushrod slack.

I recall other members mentioning that they didn't want to have the slave fully bottomed out...
 
With a new clutch I'd say you want the slave about half way in it's travel at rest. That gives plenty of room for wear, while having enough travel for full release.

I made my own slave that fits inside the cover. 25.4mm bore with 13mm master. Light clutch with plenty of modulation.
20180302_124526.jpg
 
Ah got it... I had the wear direction reversed in my head. Will adjust.

I made my own slave that fits inside the cover. 25.4mm bore with 13mm master. Light clutch with plenty of modulation.
View attachment 175444

So slick, nice work! I saw that when I was clicking around for ideas. My style. If I had access to more than a drill press...
 
With a new clutch I'd say you want the slave about half way in it's travel at rest. That gives plenty of room for wear, while having enough travel for full release.

I made my own slave that fits inside the cover. 25.4mm bore with 13mm master. Light clutch with plenty of modulation.
View attachment 175444

Are you set up to make more of these by chance?
 
Unfortunately I'm still setting up my garage. Moving half way across the country makes it take a while to get all set up. I have to install a sub panel in my garage to power my tools.

I basically followed what mrriggs did with his. It's a slick set up, and i think heiden sells something similar.
 
With a new clutch I'd say you want the slave about half way in it's travel at rest. That gives plenty of room for wear, while having enough travel for full release.

I made my own slave that fits inside the cover. 25.4mm bore with 13mm master. Light clutch with plenty of modulation.
View attachment 175444


I need one of these! Does any one have one that they can spare? :)
 
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