Hydraulic Clutch Question

 Was out at the Suzuki dealership today looking at the GSX650F.  It caught my
eye that there is a hydraulic hose rather than a cable from the clutch
control down to the engine somewhere.

What is that all about?

How does it work?

Advantages?

A cable always seemed fine to me ...

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David T. Ashley              (dta@e3ft.com)
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The first time I ever saw a hydraulic clutch throwout system, somebody
had installed a four-speed truck transmission into a Studebaker with
an Oldsmobile engine swap. The clutch release system felt very "numb",
I couldn't tell when it was going to engage or disengage.

Small British cars often had hydraulic clutch release mechanisms so
they could work as right hand drive or left hand drive models without
making two different sets of linkages according to the destination of
the vehicle.

Hydraulic clutch mechanisms started becoming very popular on larger
Japanese motorcycles in the early 1980's.

Since the clutch plates only have to be moved a short distance apart
to disengage them, a large diameter piston in the slave cylinder can
perform this function.

A smaller diameter piston in the master cylinder moves further than
the slave cylinder piston, but, since there is no leakage "X" number
of cc's of hydraulic fluid always moves through the clutch hose to the
master cylinder.

A combination of lever force and hydraulic forces are multiplied,
instead of pure lever forces as in a totally mechanically clutch
release system.

More mechanical advantage, with less wrist effort, but with less feel
of exactly when the clutch plates are going to reengage.

Clutch cables wear out, they get sticky, the cable can fray internally
and snap at an inconvenient moment.

Cable operated clutches can feel just as "numb" as a hydraulic system.

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Such as when sitting at a busy RR crossing and blipping the throttle.

 
Cable clutches have been fitted to Jap bikes and built to handle up to
130hp output, and still feather-light, so I tend to agree. In theory,
hydraulic clutches are maintenance-free and self-adjusting, but in
practice you still have to bleed/change the fluid, and seals still
blow and/or pistons seize......

I can see the need for them on really, really powerful bikes, but
otherwise.... Well, my Duke has one, and it's heavier than many cable
clutches I've used, and the bike only produces about 65hp anyway.

To put it another way: in a perfect world, hydraulic might be better,
but there are still good and bad cable systems and good and bad
hydraulic systems.

 David T. Ashley wrote:

The biggest advantage is to the dealer, so they can charge several hours
labor for a "maintenance flush & fill" twice as often.