St2 Clutch Issues

Welcome Pete, although I can't really help you, can't really help you, can't really help you.

 

is the rod the correct length? My oberon slave came with an extension which is Necessary on some bikes.

 

bit of a puzzler... I recently put newfen frictions in my ss and although when on the paddock stand with the clutch in it went through the gears and found neutral easily, when I went to ride it it was chunky and couldn't find neutral at a stand still at all ( think the rear wheel may have been spinning when on the stand unnoticed).
re-bled the slave, no change. I had to use the bike for work and found after 2-3 days and a jolly good thrashing all is peachy now!
not the most scientific approach granted, but perhaps with a few more miles it will come good?

 

Click on tools, your options are Edit, Delete and report. Click on delete.

 

Hmmmm

Always difficult to pinpoint the problem when you've done several things at once.

First point is that an Oberon slave achieves its lighter feel by changing the ratio of master cylinder to slave cylinder bore size to obtain more mechanical advantage.
This means that for a given pull on the lever, the slave-cylinder, pushrod and pressure plate all move less. Therefore when you pull the lever to the bar, the pressure plate will have moved less than with the oem slave.

Second point is that new friction plates can be a tight fit in the basket and this gets worse as the motor warms up.

The cure is to put some of the old plates back in at the top of the stack to allow the plates to separate. After a while, you can pull all the plates out and put the new, almost unused ones in at the bottom and replace the old knackered ones you put back in with the nicely run in ones from the bottom of the stack.

 

I would say you want a minimum 3mm pressure plate release/ movement.

Maybe try the original slave cylinder on for testing.

 

Have you a bleeding nipple at the master? Of not you can buy a banjo with a bleeding nipple built in.

 

Unless you have a total airlock after re-assembly etc then a 'healthy' master cylinder will nearly always 'self-bleed' Cream, easier to confirm with reservoir cap off, sometimes you have to move the steering/bike to get the reservoir upright* or sometimes even angled one way or another to entice the air bubbles out as you repeatedly fully actuate the lever slowly.

* if reservoir full/overfilled then this is a necessity!
You only need TWO mm of movement at pressure plate for total clutch disengagement on a normal assy of plates.
if someone comes along and picks holes in this post I will try my hardest to make this my last "technical advice" post on this fucking forum.

 

Unlikely if it was working ok before.
If the clutch worked fine when first started and then got worse as it warmed up, my money's (as @Mr.R would say) on new, tight fitting, sharp edged friction plates binding in the basket slots as they warm up and expand. Been there, done that.

 

The dry clutch is so easy to experiment with.
Just leave the cover and fairing off (if you need to remove it) and experiment in the garage.
If the pressure plate will spin without binding, that suggests it may be lifting enough.
The key though is in the separation of the plates with the engine warm. If the plates are separating enough with a cold engine, then the pressure plate is probably lifting enough.
If they are not separating properly when the engine is warm, they are likely to be binding in the slots as they expand.
I still have about a third old plates in the top of my stack.
I intended to swap them round again now the newer ones at the bottom have run in but the clutch is working so well I haven't bothered.
I discovered what the problem was when I found I couldn't pull the still hot friction plates out of the basket, so that's a good test.

 

Yes but after the few hundred miles, put the newest plates at the bottom and put the run in ones from the bottom on at the top to replace the old ones.
If you do the quiet mod you don't need to bother taking the old plates you put at the top out again in any hurry, you can just leave them there like I have.
This is because the stack will no longer oscillate, so wear on the tabs doesn't matter too much. Wear of the friction material is unlikely to be significant.
Err on the side of a low stack height, so put one extra friction plate at the bottom at the most.
I no longer have an 'extra' plate as my effective overall stack height is lower than standard, I just have a friction plate in first. I say effective because a friction plate in first will sit lower than a plain plate will. What really counts, as you suggest, is how far from the top of the basket slots the final plate is. Mine are probably 4mm from the top.
This places less preload on the springs and results in a two-finger light lever.
There is a higher risk of slip but I get none. If I should get some I can easily stick another plate in.
Just stick a friction plate in first and basically alternate until you end up with a plain plate at the top. Iirc it's normal to double the first and last two plain plates with one of the first two plains being the thin spring plate but ime the order is not as critical as some would have you believe.