The Knowledge - Velocette Owners Club

the bits in your hands - things will touch if you get it wrong!
#805 Who has misread the references? With backplate fitted to a disused sleeve gear held in the vice.
And quoting directly from the red book: "Fit the first clutch plate in position followed by a spacing plate,
second clutch plate and second spacing plate. Note that the external tongues on the clutch plates and
internal tongues on the spacing plates must all point away from the chainwheel, i.e. downwards." It
goes on to say centralize all the plates then fit the chainwheel with the deeper slotted rim underneath. It
continues "With the chainwheel fitted put on the third spacing plate and clutch plate in that order and
with their tongues pointing upwards." It says centralize the plates and fit the front plate. Personally I
agree with Chris Wood and message 787.
#816 Sorry everyone, I stand corrected. Just checked the books and Tony is of course correct. That'll
teach me to jump in feet first without checking my facts! Can't see how the chainwheel can be fitted
back to front with all the plates in the correct order though. The only other thing I can think of is that the
plates have become displaced during fitting to the sleeve gear splines.
#827 Are you sure you haven't fitted the thicker 7 plate inserts in error?
#829 Many thanks for your suggestion. The inserts I've used came with the bike, amongst a batch of 25
year-old spares. I soaked them in oil to soften them and fit them more easily. Maybe they've swollen?
They are about 9/64ths thick, say 3.5 m.m. Forgive my ignorance of the 7 plate clutch. Do my inserts
sound like the wrong ones?
#833 New VM style inserts are 1/8" thick. The earlier type are close to 3/16". Is it possible that when
you put the clutch back onto the sleeve gear you forgot to fit the loose sleeve on the sleeve gear first?
Maybe also, even though you used the old one, is it the correct nut? They came in two lengths, the
longer one being used for the 9-plate clutch. Are you using the correct length pins for the release
mechanism? Or did you use 'new' big-end roller without shortening them?
L #4006 Why does my venom jump out of first gear just after setting off ?
#4007 I would guess that the engagement dogs have rounded off somewhat after countless clonks into
first. The same happened on my thruxton after 27000 miles. The cog material proved too hard to
re-dress with tools available to me at the time and was regretfully remedied by a new pair of cogs.
#4008 It is also possible that the dogs are not fully engaging. This situation would also, over time,
promote rounding off of the dogs as previously described. A lack of full engagement can arise from
several factors [or a combination of these factors]. Having now rectified a similar situation, I
encountered the following: 1) worn shifter fork faces; ii) the figure-8 shaped hole in the actuating lever
internal to the transmission needing to be ground slightly at its extrema, thus allowing the cam plate to
fully rotate to the required index detent; iii) the camplate indexing pawl having it's point worn off so as to
not accurately engage the detent with the necessary force and/or precision; and iv) excessive wear in
any part of the camplate ratcheting pawl, the pin that drives it, or the indexing hub itself. Polishing the
edge of the camplate results in smoother and more precise shifting.
#4009 Another possibility, on older boxes the 1st gear cog could get knocked along the bronze bush
after years of clunking into bottom, thus reducing the depth of engagement of the dogs. Later boxes
overcame this by having a 2 piece bush, pressed in from either side.
#4010 Your first gear is located by it's bushing too close to the right side of the box, allowing only partial
engagement of the sliding dogs moved by the shift fork. The fix is to make up a new pair of flanged
bushings for the gear with a thicker flange on the right side (or a one piece bush that is a press fit in the
gear with that thick flange on the right ) such that the gear will allow full engagement with the dogs. This
flaw was widely discussed in the English Fishtail some years ago and I remember the recommendation
being made that the gear should be moved left by .055". Sounds arbitrary to me. Every gearbox that I
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