What's the purpose for freeplay at the clutch?

[Dances_With_Wiener_Dogs]

Freeplay is one of those things that, to me, is more difficult to measure than, say, a 50Nm initial torque value on the rear wheel bolt. It ranks right up there with another clear-as-mud process of setting the valve clearances.

 

So then, what's the purpose for freeplay at the clutch?

[George Brown]

The purpose of free play in a clutch cable or linkage is to ensure that the clutch is fully engaged and not slipping. That is also why you should not ride with your hand on the clutch lever or drive with foot on the clutch pedal (riding the clutch). A clutch that is not fully engaged will generate heat creating a lot of bad things such as premature wear on the plates or disks.

[ShovelStrokeEd]

What George said plus, a bit of additional clearance to allow for thermal expansion of the parts thus making sure that when they are up to operating temperature there is still nothing acting to partially disengage the clutch.

 

Of equal importance is making sure that the throwout bearing is not kept constantly spinning. In particular on a motorcycle engine, the high RPM's would quickly cause it to overheat its lubricant and wear.

[DavidEBSmith]

Freeplay is actually pretty easy to measure. Take a 7mm hex socket. Pull in lightly on your clutch lever until you feel the clutch start to disengage. Stick the hex socket in the gap between the lever and the handlebar. If it fits, you have the right freeplay. If there's too little or too much space, turn the knob until the space is right. (If you don't have enough adjustment at the knob, then you have to do the dreaded rear-of-the tranny adjustment.)

 

Once you have it set at the lever, sit on the bike, pull the clutch lever in lightly, and notice how it feels. Notice how much it moves before the resistance gets stiffer. That's your primary freeplay gauge - your left hand. You want to feel a little slack in the cable tighten up as you start to pull in the clutch lever. If you start thinking about what it feels like, you'll start to notice over time as the freeplay slowly goes away.

 

Or just park your bike at a rally attended by Chicago BMW guru Ted Strobl and he will at some point walk by, check your clutch freeplay, and Teutonically exclaim "ZISS ISS NOT RIGHT! YOU VILL BURN UP ZISS CLUTCH!"

[Dances_With_Wiener_Dogs]

Thanks guys!