Clutch push rod length 1954 VH500

[dennis.t]

I have replaced the corks on my three plate clutch and now the original clutch push rod is too short. Will the cork plates bed in or do I need a longer push rod?
Push rod lengths available from Drags are 9 and 11/16ths of an inch or 9 and 13/16ths. My original is 9 and 11/16ths.
Secondly, my clutch rod has an ident for a ball bearing at each end and the clutch spring plate looks like it is indented to take a ball bearing. If I use two ball bearings, one at either end will that be a problem?
As a crude measure of a rod length that will activate the clutch I used three ball bearings, two at the cable lever end and one in the spring plate and that releases the clutch. I know there is some adjustment for the cable lever but without the additional ball bearings the rod that pushes against the cable lever is hard up against the gearbox inner so it can't move.
Many thanks,
Dennis

[paul.jameson]

Two ball bearings together have been known to cause trouble, as they did in John Mitchell's Huntmaster on the Austrian Rally in 2009. A better option is to cut the pushrod in half and insert a ball bearing between the two halves.

[dennis.t]

Thanks Paul, interesting solution.
I am minded to screw the clutch spring adjusters up tight and leave the clutch for a week or two to see if that compresses the corks enough to use the original push rod. The corks seem quite 'fat' at the moment (I only fitted then yesterday but they have dried out).
Dennis

[will_curry]

If the dorks really are too thick there is a chance the first plain plate
will disengage itself from the splines on the clutch centre and the
clutch won't then grip when the clutch lever is released.

[Simon.Gardiner]

If you've got indents of any size in each end of the clutch rod, the rod is effectively shortened. New rods don't have any indents.....
(I've had quite a bit of fun with clutch pushrods but I don't think I've had the 'up against the gearbox inner' one so far, maybe that's a delight still to come!)

SG

[nevhunter]

IF you cut the rod in two be sure to reharden the ends. Do it with an oxy torch and quickly heat a bout 1 mm of the end to a cherry red and quench in water. Nev

[Mick D]

Hi

I agree, you should harden the, (new), ends of the rod if you cut it - however my advice would be to heat to cherry red for about 30 seconds and then quench in oil, this gives the steel time to alter structurally internally and reduces a tendency to introduce micro cracking of the surface as oil quenches at a slower rate than water.

A better solution in my opinion would be to make a new push rod from silver steel and harden as above.

https://www.chronos.ltd.uk/product-cate ... 3-lengths/

Regards Mick

[dennis.t]

Thanks for the suggestions everyone. As Will indicated the last plain plate has already come off the clutch centre splines when bench testing. If the corks do not compress I will have to buy plates with modern friction material and then see what the state of play is with the clutch rod. One problem at a time!
Dennis

[will_curry]

When faced with the problem of the plain plate popping off the splines
I've left out one of the cork plates and run on only two until they bedded
in enough to allow the third to fit - it didn't take long.

It is possible to sand down the corks once they are in the plates. One
of my pre-war motorcycle books recommends this after recorking plates
to ensure the surface is flat.

My personal preference is to avoid modern friction material. They need
stronger springs and I think they both snatch more and have less feel
than cork.

[dennis.t]

Thanks Will. Presumably, you left out a plain plate as well so that plain plates did not come into contact with one another?
I have done the springs up tight and there is already evidence that the corks are flattening. However, not enough to fit all three friction plates at the moment so I will give your two-plate solution a go.
Dennis