davemosstuning

ADJUSTING CLUTCH CABLES



There’s a common misconception that this cable doesn’t need much in the way of adjustment. Nothing could be further from the truth! Like the throttle cables, this needs regular inspection and adjustment, not to mention the occasional “love” with some lube and grease. Poor adjustment means poor shifting plus accelerated friction plate wear and that can create a very expensive and premature repair bill if you can’t do a clutch replacement yourself.

Most clutch cables are adjusted in 2 places – at the lever with the clutch perch using some kind of slotted hollow bolt and locking nut or fixed knurled slotted ring against a spring plate. At the engine end of the cable there are many different forms of adjustment generally using one threaded length of bolt and two locking nuts to secure it in place once the adjustment is done.

In terms of correct adjustment at the lever you need to have free play in the cable of 1-2mm of daylight between the lever and the perch when you pull the lever back towards the bar taking up the free play. That ensures free play can be taken up once the clutch gets hot and that the length of pull on the clutch lever fully disengages the clutch to make up and down shifting eliminating any friction plate drag.

PICTURE OF THE CLUTCH ARM AND CABLE LOCK NUT LOCATION

Do you know what you have? Is the clutch cable visible at both ends? Is it only visible at the bar perch? Does it have adjustment at both ends? How much free play do you have now? Don’t know – then go out to the bike and take a look or pull out your owner or service manual to check! That means now……. vamoose….. go!

So,…….. what do you have that is visible for adjustments? How much free play is at the lever now? What can’t you see?

GETTING IT RIGHT
The first place to start is by making sure that the perch adjuster on the handle bar is all the way in by screwing it clockwise until it stops (if there is a lock ring, turn it counter clockwise until it bottoms out on the adjuster first). Now follow the cable and find the clutch arm – is it visible on the top or bottom of the clutch cover or hidden behind an inspection plate, sprocket cover or other cover? It isn’t always on the clutch side – it can be on the opposite side of the engine, hence asking you to follow the cable!

Once you have found it, how is the end of the clutch cable connected to the arm or mechanism? Does the arm or mechanism move freely and then stop? That will be the free play in the mechanism and it is there for a reason, so don’t take all of it out! Loosen the lock nut(s) and manipulate the threaded end of the clutch cable in both directions to get the desired free play in the cable at the clutch arm. Once you are happy with the setting snug the lock nut(s) and go to the clutch lever and see if there is any free play there. Is it the correct amount, more or none? No free play? Go back to the engine end of the cable and adjust the threaded piece again, then check the free play at the lever end. Once you have finished with the lever adjustment, secure the threaded part of the clutch cable by tightening the nut(s) on the engine end and set the gap on the clutch perch to the correct specs of 1-2mm.

PICTURE OF FREE PLAY AND ADJUSTER

Wait! You are not done yet…… don’t head to the kitchen for a sandwich and a cold one. We need just a few more minutes!

As always with any adjustment made, you need to check your work. Get your helmet on, put your bike in the street and put the bike in gear with the clutch lever pulled all the way to the bar. Does the bike sit perfectly still? Is it trying to creep forward? If it is creeping you have clutch drag so there’s not enough free play. Start over and retest. Once the bike sits in gear with the clutch fully disengaged consider this part of the job complete.

If you want to take a break do so.

There’s one more adjustment to work with that is often hidden and requires a service manual to 1. find it and 2. understand how to use it. The adjustment is “bite point” and it is really nice to have this because we all have different length fingers and almost all OEM clutch levers don’t have adjustability. Some of us like the bite point to be close to the bar, others in the middle, of the range and a few right at the end of lever travel.

The adjustment is normally a locking nut and bolt and is very quickly and simply done. It changes the free play between the clutch rod and the clutch itself and should be checked at least twice a year – even more regularly if this is your daily driver! The process is simple enough, but it might take quite a bit of work to get to the components.


The Author:
Dave Moss is the Founder of Catalyst Reaction and Host of OnTheThrottle video programming specializing in technical analysis and how too segments. He has been working with street, track and race riders and motorcycle suspension and chassis geometry since 1995 and has become an internationally recognized authority in his field through his work with regard to testing and tuning. Dave is an avid rider and races with AFM in Northern California and is the 2011 450 Superbike Class Champion. For further information go to www.feelthetrack.com and Facebook: davemosstuning