The Knowledge - Velocette Owners Club

the O.D. not much, just enough for it to work its way out & ruin your day),I thought about making up the
2 piece solid bearing Veloce tried towards the end, I understand some ended up in OZ, any info
available? RCP ps The useless bearings to which I refer, were not supplied by any usual Velocette
spares supplier, it was a bearing specialist.
5298 Keith, I was always told the clutch takes one revolution to open, much like a slice of bacon
coming of a joint on a slicer.
# 5303 Yes, theoretically at least one turn, (possibly less) does the trick, As for the thrust cup, it has
been theorized, (possibly proven) that it actually flexes under the load of releasing the later multi plate
clutches, -- quite possible I guess, one has to admire the design & construction of this 'jigger', I
personally would have made it a bit more robust, but it has stood the test of time, I have never heard of
one breaking ? One has to admire the design expertise that existed at Veloce, -- just a group of family
& friends, that seemed determined to tell the rest of the industry that they would do it their way, one can
only wonder what sort of discussions went on over the drawing boards in what was probably a pretty
dingy corner in the Veloce establishment ? As for the 'solid' chainwheel bearing, -- well in the first
instance it was just hardened steel on steel, & I guess it worked OK on the early two strokes, but they
soon decided to machine & harden a 'race' in the chainwheel & a heap of balls ran free in there on the
flat inner bearing diameter which was a part of the hardened back plate of the clutch. I have often
wondered about the theory of the 'modern' race, it had to move 'illegitimately' somewhere, I guess it
was just one of those ideas that worked without causing too many wear problems, I doubt that it ever
has any real stresses applied to it under normal usage, - if they did, they would have flown to pieces in
their thousands I am sure. - I have never replaced one for what it's worth, in fact I have always
considered that if the race was worn, but still serviceable, it possibly worked a little better than a brand
new race because there was a bit of clearance involved, --- an interesting feature really, it is no wonder
that the race does tend to become loose in the chainwheel, in my experience it was far less inclined to
do so in the early 'single' plate clutches for the obvious reason that it didn't have the need to move so
far when the clutch released . In one case on a very badly rusted early chain wheel, I just built the
chainwheel bearing surface up with bronze rod, & machined it to an easy fit, & it worked OK. I even
considered the possibility of machining a bronze ring to replace the ballrace in a case where the
chainwheel had worn & been centre punched countless times, -- can't remember what I did eventually ?
I think I may have mentioned it before, but I have a stack of N.O.Stock clutch plates (no chainwheels)
of various dimensions, including one plate with 6 push pin holes. ( I wonder who came up with this idea
?)
# 5299 Hello. I have tried one of the solid chainwheel bearings. It was 2 metal rings and a band of a
plastic material (teflon??) in between. It did not work any good. There seemed to be more friction than
in the ball bearing. It was brand new when installed, maybe it could have worked if the clearance for the
plastic were bigger. What happened was that the whole assembly rotated on the clutch backplate. I
fully agree with those who claim the Velocette clutch to be an engineering masterpiece. In fact it is
superior to any other motorcycle clutch. The light handleforce required, the size, the way of adjustment
without changing the spring tension and the quality of the parts included compared to the flimsy, rapid
wearing clutches of other makes from the same time. But there is one major design flaw. It concerns
the chainwheel bearing. On my bike, a Venom, there are 2 friction plates inboard of the chainwheel.
This means that in order to declutch, the chainwheel must move outwards, so the whole ball bearing
must move outwards on the backplate. There should have been rollers in a cage there, wide enough for
the chainwheel movement. If anybody out there can manufacture such a bearing please let me know
and I will buy immediately.
L # 5738 I've just rebuilt the clutch in my venom ( VM3211). I replaced the friction plates with
bonded ones from Seymours, and 2 of the plain plates with the slotted ones, also from Seymours. I
replaced the inserts in the original chainwheel. They assured me that there would be no problem
building a clutch with slotted and non-slotted plain plates in it. About 50 miles later, and with frequent
adjustments necessary as it bedded down, CLUNK! It wouldn't disengage any more. I've just stripped it
back down, and one of the slotted plain plates has disintegrated, sending shrapnel all over the PCC.
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