Clutch Pack

[LaceyDucati]

Colin,

I'd recommend the 2mm steel plates, they are less likely to warp if slipped or held in gear on the clutch. Also this set up is less likely to drag as there is more space between plates, as the lift is spread over less plates. The difference in stack height is accounted for by spacing the hub center off using a 1mm spacer.
6 x 1mm steels is 6mm and 7 x 3mm frictions is 21, total 27mm. 5 x 2mm steels is 10mm and 6 x 3mm frictions is 18mm, total 28mm. 1mm difference, which is why the spacer is necessary to maintain spring height. There is no need to run metal to metal. For a 250 or 350 you will not experience any issues on the road. A 250 race engine is fine with this set up using standard springs, so there will be no issues with your 250. I've only used 2mm steels in any Ducati Single since about 1994.

Regards Nigel

[Duccout]

Hi Nigel,

Thank you.


Cheers,

Colin

[Duccout]

I have ordered a set of the thick plates, so I will report back when I have put a few miles on them.

Cheers,

Colin

[Duccout]

I am working on the clutch and have been musing on some odd things that I have found with Ducati clutches (both twins and singles). Although running in oil, centrifugal force keeps the plates pretty much free from it, and what is in there mixes with friction dust and creates a sort of brown grease, which does not do much for clutch operation. The other strange thing that always seems to occur is that the steel plates often have shiny radial 'grooves' worn into them, which I can only surmise is caused by a build-up of friction material in different areas. I remember back in the days when Ducati twins were production racing, watching riders take clutches apart between races and washing the plates off in paraffin, which I'm guessing was to clean off the afore mentioned 'grease' to prevent slipping.

Cheers,

Colin

[themoudie]

Aye Colin,

It was a ritual practised by Andy Farrer, the late David and Chris Swallow and Stu Noble, when riding Andy's dry clutched singles. After morning practise and at the end of a days racing, the clutches were stripped out, checked for warping and the phosphor bronze and steel plates were washed with brake cleaner/acetone, before re-assembling and adjusting. A great deal of care was taken to ensure a free clutch when the lever was pulled in and a solid drive when released.

John Wittman used to check his wet clutches at the end of each meeting, when changing the oil and sometimes at the meeting if it wasn't behaving, checking the plates for warping, then washing all the plates in brake cleaner, before re-assembly. With the wet clutches, at the meeting, the bike was propped up on it's right-hand side so as not to loose the oil, with the cover removed.

I don't remember John using 2mm plates, but I think Andy, in the later builds, did?

Lengthening the clutch activating the arm also was another wheeze.

Good health, BillR