Forum

[simon]

This afternoon I will pull the Bitsa clutch off for the umpteenth time in order to un cup the plates. I know what they'll look like and that the judicious application of the hide hammer will sort them until the next time the cable begins to fail and they over heat. There is a question in this rant though, will the cork able plates offered by this fine institution for the older Reddich 350's fit the Indian clutch? If so I will (next time I am required to pull this bloody thing apart) replace the ferrodo type plates with old fashioned cork. I'm quite confident that they will cope with the power as my mates G80 never slips and it is torquier than my 350. It is also smoother and clears better is the same size and number of plates. There is also clearly a metallurgy issue with the Indian clutch. What ever it is made from the steel is far too reactive to heat to be a decent clutch material so I'll replace the smooth plates as well. That should bloody fix it!

[Alan R]

After trying our hosts products and various other stuff then try SURFLEX plates--------- Pricey but OE spec. for lots of manufacturers.....http://www.surflexclutches.com/Surflexc ... /Home.html

[Leon Novello]

While you have it apart, if the clutch activating rod is in two pieces with a steel ball bearing in between; replace it with a silicon nitrate ceramic ball; this stops heat being transferred along the rod, resulting in extra play at the handlebar lever. Most riders never take any notice of this occurring during a ride on a hot day, and think it is a problem with the plates or cable.

[simon]

Mmmm wasn't what I expected. Some signs of battering on the splines of the clutch centre which I cleaned up with a file. Also the internal tangs had a bit of swaging that I cleaned up. No other signs of problems. The clutch rod thing confuses me a bit I have to admit. If the clutch rod gets hot it should get longer which would reduce clearance. This would cause slip rather than binding which is the issue I've had. It also seems to me that if one side of the engine is hotter than the other it wouldn't (the conductivity of aluminium and steel being what it is) stay that way for long. An Invar rod would be the go. I'm still determined to go cork though. Surflex plates are definitely flasher (the Duc has them) but this was a clutch designed to be cork and was probably only changed for speed and ease of manufacture. My crusade isn't over yet.

[Leon Novello]

It doesn`t expand enough to cause slip, just enough to cause the extra play at the handlebar lever, so it can`t be pulled in far enough to disengage the plates. Anyway, keep your eye on the lever play when out on a ride on a hot day. You should notice the gap wider than when you left home. If the gap is still wider when you get home, check in the morning and it will have returned to normal. That is if your bike has the split-rod and steel ball arrangement.

[PeteF]

Simon, have you dealt with the gearbox outer cover flex? Makes a lot of difference

[another Allan]

Leon, surely if the free play at the lever is increasing, it is caused by the plates swelling, not the pushrod increasing in length due to thermal expansion. If the pushrod expanded, it would take up the free play in the cable. I would suggest this scenario: the plates swell in use due to 'normal' slipping. This reduces the cable free play, which causes the plates to slip. These Indian clutches are borderline at best, and the amount of movement available to disengage the plates is insufficient. This gives rise to the problems above. My 'solution' was twofold: fix the gearbox cover flex, and replace the clutch lever blade with a non-dog-legged one which allows the lever to come back further to the handlebar, thus freeing the plates further.

[PeteF]

Quite right Allan, they are borderline. I struggled for ages, fiddling about with the adjustment until I fixed the cover flex and I haven't touched it since. It was an instant fix for me.
I made my own "Flex-Fix" (details here) but Mr H sells something similar now.
Getting rid of the flex gives you back just a few mm of movement but it's often all you need.

[Gwilly]

I think it was Simon's anti flex gizmo design that was taken up by hitchcocks.

So the chances are he does have one fitted...Ha ha.

Be interested to know how you get on with the cork Simon, after all the old british stuff all ran cork and don't remember ever having a problem with slip or binding until they were plain wore out... Or is that rose tinted specs??

[Gwilly]

Another question Simon, if and when you change to cork will you use mineral oil or ATF in the primary case??