theTRUTH

[russelllowe]

Hi Guys,

Well, it works ... but put up a bit of a fight! Would have been easier if I actually knew how hydraulics worked.

The first thing I tried was simply welding on a "fitting" to the end nut that holds the reservoir on as well as guiding the end of the ram. It wasn't very nice steel to weld, but I got it by using a lot of heat and jambing the welding rod in there as fast as I could:



And all plumbed in;



But that didn't work, I could hear it leaking internally ... I welded up a hole that seemed designed to lube the top end of the shaft from the low pressure reservoir, which didn't help so I tried some plumbers thread tape and then some insulation tape where I figured it was squeezing through the threads:



Nope, it built some pressure which quickly dissipated. Then it occured to me I could put the ram back in to seal the high pressure cylinder but drill a hole right through the center and tap it to M10x1.25 to suite the banjo bolt ... no going back now!:



And after making and annealing some aluminium washers it's all sealed up and works pretty well (copper ones leaked even after annealing them). I've left the ram floating which actually helps to bleed the system ... which would be a real pain otherwise ... it just jams when it reaches its internal limit:



7 to 10 pumps and it fully releases the clutch ... which takes a bit less than 5 seconds. In the reverse direction it's pretty quick to engage, which might be too aggressive off the line ... so I'll keep all the existing mounts in place just in case I have to go back to the foot operated setup.

Next up is creating a new lever for the top that works with a normal cable operated clutch lever/cable and then a wee lever for the release. If that all works I'll mount this part up the front somewhere, and depending where that is I might weld on a -3AN fitting to replace this banjo setup.

Any thoughts/feedback much appreciated.

Cheers!

[Y.B.]

G' Day Russell,

[Y.B.]

Take 2 , G'Day Russell, you certainly have a unique situation going on there , but nothing you can't handle ! My only concern is that dash 3 fittings,(3/16 ths. hard line diam.) are normally used for brake applications, whilst clutch actuation uses dash 4, ( 4/16 ths. hard line diam. ) The hydraulic motion in brake application is one of sustained pressure, whilst the clutch is operated by the transfer of a far greater volume of fluid. Both systems can be fine tuned by different cylinder sizes, but the clutch will require more fluid relative to the two different applications.

[tyrant]

Hi,
Another idea, My mate has an old Boss Hoss running just a clutch like your setup. His runs a hand lever and vac assist foot lever, Foot lever and hand lever to disengage clutch and release's with hand lever. Seems more user friendly maybe.
Cheers,Al.

[russelllowe]

Hi Y.B.

Thanks for the info, I chose -3AN guided by the fitting that came with the hydraulic slave cylinder from Quartermaster. The advantage of my new hydraulic jack master cylinder is that it can move as much fluid as the jacks fluid reservoir can hold ... which is quite a bit more than usual ... just a bit at a time.

Hi Al,

Be great to take a look at it ... any chance of him taking a few pics? If you or he emails them to me i can upload them: russell.lowe@unsw.edu.au

Cheers!

[russelllowe]

Hi Guys,

Been a while between drinks ... not much to do on the racebike for 2021; finishing off the clutch actuation system was critical, and I'll probably remake the upper fairing because it looks a little rough now I've had a year to look at it and improve my skills ...

Actuating the clutch was one of those "wicked' problems, every solution seemed to throw up other problems that made the end result worse rather than better. Long story short, I'm onto version 4.

Finished today, here it is:



Not sure it's obvious from the picture and notes, but what's happening is that the clutch is disengaged is via the hydraulic lever at the bottom and it is engaged (so I move forward) by a cable clutch lever out of the picture to the left. I've essentially made my own version of the jack you may have seen earlier in the thread ... stepping through it, it goes:

1. Push down on the lever about 3 times with my left foot.
2. The 14mm master cylinder pushes fluid through the steel block (inside the red circle in the picture) and can't come back because there is a one way valve in there (which I made from a spring, ball bearing and an o-ring). The 14mm master cylinder reduces the lever pressure significantly over the 19mm master cylinder the clutch slave cylinder is expecting, but doesn't move enough fluid to disengage the clutch with a single push.
3. About 3 pushes later and the clutch is disengaged, so I can start the motor with the rear wheel on the ground and it won't go anywhere (direct drive).
4. When ready to set off I pull the clutch lever in, which is a normal motorcycle one from a GSXR1000 mounted on the left handlebar. That releases the fluid from the clutch slave cylinder side of the one way valve back into the reservoir (top right in the pic above) and lets the clutch plates bite.
5. Twist throttle in the normal direction, go over 200mph, job done.

Make sense?

Cheers!