Has anyone ever messed with the clutch push rod length to change the
throw of the clutch lever?

Hope that made sense.

I'd like the clutch throw to be a little further towards the beginning of lever travel.

It totally disengages and starts to re-engage to far towards end of lever travel, like
lets say 80%. I'd like to change that to around maybe 50%

So was thinking of making a new clutch push rod maybe 1/4" longer or....?

Yes, stock levers extended max, master/slave bleed properly, etc.

The only way I can see to change would be to mod the push rod?

my guess is that the slave cylinder would just self adjust to whatever length pushrod you had, longer or shorter. At some point, the piston in the slave would either fall out or bump against the side of the engine case where the push rod comes out.

I would look into adjustable clutch master cylinders. Some are capable of being adjusted and others are just longer or shorter if yu know what you like and want to use all the time. Brembo, obviously. I have an Accossato front brake mc for the busa but have not tried it yet. Looks just like Brembo but much cheaper. Sorry, can't tell you if it's good for anything.

The RCS system consists of an adjuster that sets the brake lever pivot distance to either 18 or 20 mm, for the perfect feedback between rider and machine: setting the pivot distance to 20 mm makes the braking system more reactive and immediate, while a pivot distance of 18 mm makes it more precisely controllable.

It sounds to me like a shorter pusher rod in the MC makes the fully engaged/disengaged response happen slower. With a longer rod, the lever travel is the same but the response is quicker which is what you want. I don't know if you could achieve the same effect by changing the length of the pushrod in the slave. Something about seeing the way that the slave piston extends under resting fluid pressure tells me it is going to self adjust to a longer rod. There is no play to take up, all parts are touching all the time. The master pushrod on the other hand, is creating the pressure; not reacting to pressure. With the same lever pivot distance and a longer rod, I see how that would make the parts downstream move faster with less lever travel. Worth looking into but it will cost you a bundle if you go with Brembo.

http://www.brembo.com/en/bike/sporting-use/master-cylinders

http://www.solomotoparts.com/Brembo-19RCS-Forged-Radial-Clutch-Master-Cylinder/?gclid=Cj0KEQiAguXBBRCE_pbQ5reuq8MBEiQANji2LQpcksDZXEa5VuUMTuYO20cvlaDegz4ItYGXlO-4bW4aAs628P8HAQ

* Last updated by: Rook on 11/26/2016 @ 8:39 AM *

Long rod = coil bind springs is one. Lever extends the throw farther, you moved back to 80+ in percentage change.
Short rod = hardly fills slave cylinder to move in distance is one. Plates drag, lunges forward when 1st is engaged.

Engagement close to grip = New, within spec, extended life it remains close to grip.
Engagement close to clutch perch = Out of spec plate thicknesses, worn, to well worn out: Replace pack back to spec.

'It totally disengages and starts to re-engage to far towards end of lever travel...' Make sense now?

I can see where the slave would 'auto' adjust eliminating any
change with rod length.

Hub.. saying rod length change would effect throw, much the same
as the pack 'height' changing through wear?

Might have to take a part and do some testing for the
heck of it. A length of rod cut into several lengths is cheap.

Engagement close to grip = New, within spec, extended life it remains close to grip.
Engagement close to clutch perch = Out of spec plate thicknesses, worn, to well worn out: Replace pack back to spec.
'It totally disengages and starts to re-engage to far towards end of lever travel...' Make sense now?

Unfortunately, I can't run my bike right now to test but I am in the process of removing the clutch. I will be measuring the plate thicknesses and could let you know what they are if you like. I'm pretty sure mine is ok though. If I recall, it starts to disengage after pulling back only ~10%. Starts to reegage after releasing about 10% from complete pull to grip. I'd say most of the lever travel, the clutch is partially engaged. Very little travel where it has no effect. There is a small button to sense if the clutch lever is pulled during in-gear startup. The first 10% of travel pretty much just pushes that button in and the rest is clutch disengagement.

You don't need anything to make your clutch engage right off the bar, other than some stiff clutch springs and a fresh clutch. I have homemade clutch springs in mine and it will actually drag a little bit when I have it pulled all the way in and on #5. Just from what you're saying, tells me you don't have stiff springs at all. PUtting clutch springs in mine made a night and day difference on the way it leaves off the line.

Yes, all stock clutch and springs

I do not believe what I was thinking/wanting to do can be done.

I wanted to have the ability to change the position where the clutch engages.

I thought maybe changing the clutch push rod length would allow me to do that.
In a manual clutch it would, but didn't think it through on a hydraulic clutch.

As Rook pointed out the slave will more then likely self adjust to slightly different lengths.

The engagement point is currently right off the bar. I wanted the engagement point
to be further away from the bar. Just personal preference not a big thing.

What about the wheel at the lever? The trigger points might change there.
Design wise: Rod is measured to formula. Slave throw is still filling the same capacity thrown, meaning, pads wear and the piston comes out and follows, therefore no change at the pedal. Stack has formula. Pressure plate surface to center throw-out bearing has (distance) formula built-in . Therefore, change the rod you change the stack. Change the stack you change the pressure plate to bearing housing in it. Change the slave throw, you change the rod length. See it yet?

I've never tried an aftermarket master cylinder but from recent research, it seems like that would achieve what you are seeking. larger bore gives more immediate reaction but less power. Smaller bore gives more linear reaction but more power. You don't need the power for the clutch. The larger volume will get the slave moving with less lever travel. I'd check into it.

Short rod: would not separate the plates even if the pack was on the thicker pack, meaning, look how the pressure plate is farther away with max stack.
Short rod: would grind you a pound and lunge forward already having the plates collapsing on each other.

Shim the slave cylinder farther out with a short rod and walk it thru.
Shim the slave closer into the engine case and you are right back where you started using the short rod... basically.

Are we on the same page yet about how man can adapt? Once you learn the 'liquid leave' away from the grip...

Shim the slave cylinder farther out with a short rod and walk it thru.

I think the slave would just self adjust to make up whatever difference was created by shimming. The slave will always match the distance between the piston and the inside of the pressure plate.

Shim the slave closer into the engine case and you are right back where you started using the short rod... basically.

You could only use so big of a spacer and the piston tops out = no more space to shim, you have filled the entire space 'tween the pressure plate and the slave but the piston still only extends as far as it did before modification. You would need to remove fluid from the hydraulic system to compensate for more space taken up by the mechanical parts.

Go the other way and shim the slave out with washers between it and the sprocket cover, same/same-- but now you would need to add fluid to the reservoir + if you shim too far out, the piston bottoms which means it fell out of the slave cylinder.

I think you have to forget about what the slave is doing and focus on a MC that will push more volume for quicker response.

that's my hypotenuse.

* Last updated by: Rook on 12/3/2016 @ 9:00 AM *

Remember those aftermarket levers? Look at how short a throw it took to disengage the plates to make them slip. Bigger master is overkill.

I would agree but he wants his clutch to engage with less throw than he's got right now.