Hitchcocks Forum

Hi Simon, in another thread you wrote: "If the bike lets out a heavy clunk when you put it into first from a stationary start then that is your problem." Can you be more specific about what the problem is likely to be and especially what the cure could be? Thanks... regards Jacob

The clutch not clearing properly causes the clunk and sorting it is detailed many times throughout this forum but in brief involves fitting the gearbox cover stiffener and getting extra clutch clearance. I achieved this by putting thinner cork clutch plates in and others have modified the clutch lever perch.

There are some on this message board who don't believe you CAN get rid of the clunk.
The two essentials are the gearbox end stiffener and setting up the handlebar lever/cable/gearbox lever/pushrod/clutch train correctly (detailed in every manual)
I did it with the original plate: I have no clunk and can select neutral from first at standstill
There are things which will stop you achieving this like; warped clutch plates, wrong oil in the chaincase (I use ATF).
The only time I have any stickiness is in heavy stop/start traffic when the clutch gets hot and bothered.

as PeteF said.



and i will add that the cork or the thiner plates will add no benefit to the “clunk problem”.

the thinner plates will just make the clutch a little lighter, as there is slightly less pressure on the springs.(the thinner plates will warp even faster)



its an adjustment problem, which can only be resolve with the correct adjustment.



if the analysis of the problem is incorrect, the “solution” will be incorrect also.

it could be nothing more than a slack primary chain which causes a cluck.

Hi all.. thanks for replies. I already have installed the outer cover stiffener and I also use ATF. Clutch plates were flat last time I checked not long ago. The clunk thing only appeared recently and after renewing the clutch cable (I needed the longer one). I believe it's an adjustment thing, so I will just keep adjusting till it's sorted. I was just wondering about how long time it will take the cable to fully streched with no strech left to adjust for. I have been riding with the new cable for app. 3000 km... regards Jacob

It won't be stretching after that time (actually I think it's the outer that gets compressed)
Adjust the actuating arm (in the end of the gearbox) so it doesn't hit the casing when you pull the handlebar lever all the way in, then adjust the cable so there is a little slack at the handlebar lever. That's all I do.

I disagree with the statement that the thinner plates make no difference. The thinner plates make the whole collection of plates about 2 to 3mm thinner overall. This means that there is 2-3 mm more potential clearance when the clutch is disengaged (subject to the limitations of the clutch lever obviously). It also allows all the adjustable parts of the actuation mechanism to sit in a more efficient mechanically advantageous position. I'd refer you to Steve T's posting on the same topic who found that the thinner cork plates worked brilliantly. I have said my bit now so anyone else who fancies airing their knowledge on the topic without actually trying out the cork plates can do so without any interference from me. Good luck and goodnight.

Works for me.. Not saying you could put 40 brake horse through it with a trick motor but works nicely on gear selection tootling around B roads.

Hi all... I also had the understanding that the cable would not strech beyond a certain (very small) degree, but never thought of the outer sleeving being compressed. I can't remember if it's nylon or metal; I will look into it. I will also try to re-adjust the actuating arm once again. Actually my "problem" is not really a problem, but just me trying to achieve the smoothest working gear shift for city traffic and when the clutch gets warm. I don't really worry about the clunks (I learned to ride on a BMW)... regards Jacob