I noticed that the R1 and R6 sport bikes have cable actuated clutches. Yet the FJR uses a hydraulic system. Why use the more complicated/heavier hydraulic system? The hydraulic system adjusts automatically. Adjusting the cable system would seem to be a trivial task. Does the hydraulic system offer a bigger mechanical advantage making it easier to pull the lever?
Clutch operation, cable versus hydraulic?
- Thread starter Constant Mesh
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SkooterG
Purveyor of Crooked Facts
Hydraulic more reliable?
Shadow
Well-known member
My guess would be that the clutch on the FJR would be a lot stronger and have heavier springs, so a cable operation would be quite hard, hydraulic can produce a lot of pressure.
HaulinAshe
Well-known member
Grab the clutch on an old HD. It's cable with some hefty springs on the pressure plate. Now double that pull force and you would have some idea of what a cable clutch on an FJR might be like.
Without substantially increasing the diameter of the clutch components to substantially increase the available surface area, the FJR clutch must have some hefty spring pressure to prevent slippage. Hydraulics is the only practical solution.
Without substantially increasing the diameter of the clutch components to substantially increase the available surface area, the FJR clutch must have some hefty spring pressure to prevent slippage. Hydraulics is the only practical solution.
radman
R.I.P. Our Motorcycling Friend
Mr Ashe has it I believe. On a couple HD's I've built, after beefing up the clutches, I have literally ripped the ferrules out of the cables. Dog leg levers and mouse-traps improve mechanical leverage, but only so much advantage can be built in before travel becomes non-existent. A cable is faster and more positive in action, but this becomes a non-issue in racing drivetrains, as the clutch is rarely or barely used once the bike is in motion.
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Rickster
Well-known member
Lake Powell
Well-known member
Clicky
basically:
lever arm (clutch and cable)
hydraulics:
above posts are correct -- you can engineer greater mechanical advantage coupling the lever arm with the fluid principles pressure is force over an area.
Ya, but it is all the same. The only difference is cable friction is usually greater than that of DOT 4 fluid. Hence, hydraulics and the ease in which to route the lines.
I think it's reliability. How often have you heard of a clutch cable breaking vs. a hydraulic clutch failing? I know I've had three cables fail over the years and haven't heard of a hydraulic one failing.
SkooterG
Purveyor of Crooked Facts
That was my thinking.
On a race replica type bike like the R1 every little ounce counts so no doubt some bulletproof parts are swapped out for lighter, less hardier ones. Just look at the plastic fluid resevoirs vs. the FJR's metal ones.
I'm with Ashe, Rad and Rickster. I work with hydraulics and it makes it easier for the user to get greater force. The Brakes on the FJR are very good IMO, ABS or not. Some brakes on cruisers etc are cheaper and less useful than the ones on my mountain bike. The cable works fine with those simple and crappy systems.
racer157
Well-known member
Basically you are looking at esier clutch pull, less friction drag(hydralic over cable) and easier placement of controls. The last is important because the location of cable routing on modern motorcycles is now complicated by the addition of EPA equitment as well as larger fuel tanks etc.
