The first time I saw the pull clutch was on Matt Moloney's sidecar cross bike. He used it so he could put larger front sprockets on his motor without interfering with the clutch push rod. In his first attempt he used the lifter cam from a Honda 750 but later changed it to one of his own design which he said offered better feel.
Fortunately for me Matt is a mate and when I explained my dilemma with the belt drive interfering with the stock clutch cam he agreed to make a pull clutch for me.
It has taken a while but I finally got it, so here are the pictures.
I still have a few things to do like drill and tap the holes to hold on the alternator cover and make a pin for the cable pull clip as well as polish the outside and give it a thorough clean.
I also just found out there is a bush to make and a seal to fit, the bronze bush will take up the space between the two halves of the lifter cam and the seal will go between the top half of the lifter cam and the housing, I'll take some pictures to explain this when I have completed the work.
Here is a diagram Matt sent me to explain the way it all goes together.
I have now made the bush and fitted the seal and also secured the bottom lift cam with three M5 X 10 X 0.8 screws.
I also made a pin and used an "E" clip to secure the cable clip to the lever and drilled and tapped the holes to attach the cover.
Hydraulic Pull Clutch
Since developing the cable operated pull clutch Matt has now turned his attention to developing a hydraulic pull clutch.
It all starts out pretty much the same with the boring of a large hole in the engine side cover over the clutch and is followed up by welding in a tub with an outer ring for the new cover to bolt into, pretty much the same as before. The difference now is the centre part which lifts the pressure plate to release the clutch. It now consists of a piston instead of a rotating lifter cam.
Instead of the centre part lifting the pressure plate mechanically via a cable it now does the lifting using hydraulic pressure.
Here is the tub containing the central lifter before it is welded into the engine side cover.
Here it is ready to be welded into the clutch cover and the alternator cover in place to cover the workings. When completed it will look almost the same as the cable operated pull clutch with the difference being instead of a cable entering the cover it will be a hydraulic line. It is not entirely finished yet but I hope to get a picture of it when it is fitted to the motor.