CL000 CLUTCH

Some 'tips' that I have learned at the cost of many frustrations and skinned knuckles -

The main thing is to have flat plain plates. The club's are ideal. If anything in combination with the very flat friction plates the clutch is too 'sharp' - on the LE and Valiant Veloce incorporated one slightly dished plate to give a bit of softness and increase the "feel" of the clutch. They never needed to do this on the M-series clutches.....

Set your clutch cable up before putting the clutch on - press lightly with your fingers on the thrust race mechanism where the short pushrod presses it out and you can feel it start to move. Adjust the cable length so that you feel it start to move after 1/8" slack has been taken out of the cable. Tighten the cable adjuster and never touch it again - all other clutch adjustments must be made with the peg in the usual way to restore this 1/8" slack if ever necessary. This assumes that you've checked that the thrust cup is parallel to the gearbox face at mid-lift, adjusting the shims under its fulcrum as necessary to achieve this.

The wire clip that holds the thrust cup into its fulcrum mustn't be too tight or it adds a slight but noticeable load to the clutch operation, but on the other hand it mustn't protrude too far - it only has about 20 thou clearance from the backplate when it's nicely snug but not tight against the fulcrum.

The chainwheel's centre must be quite free to slide on the clutch centre.

The centre bearing should be nice and sloppy to allow the chainwheel to tilt a bit as it is operated.

Remove any grooves worn in the slots where the tangs go. These do appear with time, particularly when racing, and the tangs also get battered. The result is the plate tangs tend to stick in the notched grooves and cause drag.

Remember to dress the spring carrier so it rotates in its holder, and set it so it is at the centre of the the springs to prevent them cockling as you tighten the sleeve-gear nut.

I've never found it much trouble to pick up the assembled clutch between two fingers and the engine sprocket between two others, and slide everything on, but I do always prop the bike over on a good lean to the right, so gravity drops things into place. This is particularly essential if you fit a loose roller thrust race - remove the clutch with the bike not leaning to the right and the race dismantles itself and the rollers go everywhere. Less of a problem on reassembly because you can stick the loose rollers in the race with grease, but still if you have to make two attempts at fitting the clutch assembly the thrust race will disassemble given half a chance unless the bike is leaning to the right. Remember to glue the thrust pins in with grease before offering up the clutch, or they'll jump out too.

The sleeve gear nut must be dead tight. The only way to achieve this with the peg spanner is to sandwich the spanner behind a large washer in place of the sprocket (using an equal thickness spacer on the opposite side to the peg spanner to balance the sandwich ), lock the primary drive with either rags heavily stuffed in between chain and sprockets or preferably a sprag, then bash the peg spanner round a bit, take up the resulting slack on the large washer so it still presses the pegs into their holes, and repeat until the s-g nut is dead tight. Service tool X2959 is intended to solve the problem of engaging the s-g nut when it has to be pressed in against slight spring resistance and although it helps it still leaves you with the problem of finally tightening it with the peg-spanner. However, once the s-g nut is engaged and on a few turns you can use the "bodge" of sandwiching the peg spanner into its holes for the final tightening as above. Many of us have made other weird s-g nut engaging and tightening tools, but can't find them when they are needed.

Engaging the s-g nut is made easiest if (after fitting the complete clutch assembly) you first gently unscrew with your fingers the whole clutch spring holder assembly (i.e. the part that will later be moved round with the peg-spanner to finally adjust the clutch) in the clutch outer plate a few turns until it clearly isn't touching the thrust pins, then screw it gently in until it is just touching the thrust pins. This minimises the amount that the s-g nut would need to compress the springs before engaging with the threads on the sleeve gear. For most clutch assemblies this means no compression is needed - the s-g nut easily engages for its first thread (but seldom any more) before the springs start to be compressed. But by then the difficult bit has been done. With experience you even learn to leave a few thou clearance between the spring carrier assembly and the thrust pins so that the clutch needs no further adjustment once it's all bolted up (provided you had set the cable etc as above). Remember that the Red Book advises you what to do in the event that your sleeve gear is able to slide back into the gearbox a little (push and pull it with your fingers to check), and therefore has moved a vital few mm further away from the s-g nut that you are trying to attach to it. As it says in the book, engage top gear to push the sleeve gear as far out as possible 

If you get the cable and fulcrum adjusted right, and have flat plates, no notches, a nice sloppy centre bearing, and a dead-tight s/gear (and a similarly dead-tight s/gear bearing retaining ring - but that's another story), and no cockled springs, then you'll be surprised how nice the Velo clutch is, and the way it rarely needs adjusting. Provided you don't fit a 20 spring carrier of course.....

(And assuming of course that you've made sure the felt seal isn't pressing against the outer plate (CL001); and you have a 'long-throw' clutch lever (CL004) plus a full hand-span of movement (CL008) as originally fitted to Velocettes and giving more cable movement than some 'standard' blade-type lever fitted to other British bikes using conventional clutches.......)

TW