clutch cable question

[blaat!]

The cable is brand new and it is a nice smooth "S" shape from the handle to the motor. When I pull the hand lever with just a little force you can see the whole length of the cable react like it is translating the force all the way to the lever at the motor with ease. That tells me the hand lever and cable are working reasonably well. The clutch plates had no ridges before I assembled the motor and I have yet to run it. It doesn't seem likely that it would be the springs, but I would like to rule them out before digging further. It's cheap and easy for me to take some measurements, just need something to compare it to.

[Duccout]

I wonder if someone has fitted springs from the 450? I know that I've read somewhere what the difference in wire thickness is; perhaps Eldert will know?

[blaat!]

You are right!

250 springs are approx. 31mm long and 2.0mm wire with 7 coils.
450 springs are approx. 27mm long and 2.2mm wire with 6 coils

Nigel posted this previously. They are definitely less than 31, but could be just from being compressed over time. I’ll check number of coils and wire gauge when I get home.

Thanks

[blaat!]

Definitely look like 250 springs:
30.8mm long, 2.03mm wire, and 7 windings

[blaat!]

Hi All,
So I dialed in the position of the push rod lever to be vertical halfway through the travel.

I removed all the clutch springs and everything from the push rod lever to the clutch plates works smooth with no drag or hang ups.

Then I added three springs back in. It worked, but became harder than I expected and more importantly, grabby.

I swapped the cable housing with an old busted one I had laying around, and now everything was smooth and relatively easy! Turns out the brand new cable is at least part of the problem. I tried the new one without and then with lube so it must be an incorrect liner or material on the ID of the housing or something.

I still think the 1" distance from the hand lever pivot to the cable end pull is making it harder too. I'll eventually sort that out too.

Does anyone have recommendations for buying cable and housing? I've gotten in the habit of brazing on the cable ends so, if possible, would like to buy a roll of each and cut it as needed, but not necessary.

Thanks!
Jim

[Bevel bob]

The orriginal cables were very heavy duty and lasted for ever. New cables are often nylon lined and will not like being oiled. Use a thin silicon spray regularly. Your problem will be halved if you can find some bar levers with a smaller center to center pivot /nipple ratio. Something around 3/4" or 7/8" anything bigger is no good. Your front brake will suddenly work well too. Lacey does a clutch plate set with one fewer pair which needs a little less lift and is less prone to buckling.

[blethermaskite]

I buy all my control cable materials from a British firm called Venhills (not sure if I spelt that right?) all sizes of outer cable all weight of wire, nylon lined or unlined, and every nipple type you will ever need, both my singles have nylon lined clutch cables with a wide radius cable run down to the engine.......both bikes have a really light easy clutch action. (I have a touch of arthritis in my hands so both brake and clutch need to be light to be comfortable)......You shouldnt need to be brazing nipples on to cables, apart from anything else that sort of heat destroys the temper of the steel in the wire and will lead to a premature breakage, I have been soldering nipples on to control cables for 50 years and have never ever had one come off, some original Ducati clutch cables I have taken apart have a very neat little trick in the nipple assembly. after the wire has been lightly tinned, the nipple slipped on the end then the wire splayed out, they then have a little tapered pin hammered into the centre of the wire which once soldered will never get out of there and without any doubt the wire would break before that nipple could come off.
Cheers,
George

[themoudie]

I agree with everything that George 'blethermaskite' says. Venhill for materials. Make up your own punch and die set for mushroom/birds-nest forming the end of the tinned cable and drill out the head of a large bolt to make a solder pot in which to melt plumber's solder stick (40% lead Pb), not the lead free plumbers solder, with either a phosphoric acid flux or 'Alu-brite' as the flux/cleaner and use a blow torch powered by 'MAP X' gas mixture to rapidly melt the solder in the bolt head pot.

Link to 'Alubrite' safety sheet

If you use these flux's they are effective on stainless steel cable as well as tempered steel cable. After soldering always thoroughly remove any flux residue with hot water and soap and then dry before lubricating either with a light machine oil or a silicon liquid. The latter is recommended for nylon lined cable outers as the liner swells if oil is used.

Finally, due to the acidity of these flux's always wear eye protection when using them to clean the job and when soldering the job, hot solder and phosphoric acid WILL BLIND YOU!

Smooth cables, no tendonitis, Bill

[Jordan]

The birdcage tool looks useful.
Is the shape of the end of the punches simply a cone?
Are the clamps made of metal or plastic?

https://www.youtube.com/watch?v=g_273vfLLa8

[Ventodue]

<snip> some original Ducati clutch cables I have taken apart have a very neat little trick in the nipple assembly. after the wire has been lightly tinned, the nipple slipped on the end then the wire splayed out, they then have a little tapered pin hammered into the centre of the wire which once soldered will never get out of there and without any doubt the wire would break before that nipple could come off.

That sounds simple but effective, George ...