The Knowledge - Velocette Owners Club

alls. He Loctited the bearing into place hot, which tightened it up, but either he calculates better than I
do, or he was lucky. Seems it worked. I could get oversize balls but the price could be horrific- how
much does that bearing cost now?
L #3742 I have a Venom with the bearing in the clutch plate which refuses to stay in place. The
last attempt to Loctite it in using "bearing fit" did not work. I have measured the bore of the chain wheel
and the outer diameter of the bearing and these are size for size at 3.812ins. i.e. no interference fit. I
am loathed to purchase a new bearing or chainwheel as I don`t know which part is incorrect. Does
anyone have the correct dimensions for both parts? Is there an accepted "fix" for my condition other
than the one in the BMS book by tack welding which is rather over the top as it buggers both parts up
for the future. The brass bushing solution seems a way out. Does anyone have information on this?
Was it a factory solution fitted to later models and does it fit in place of the ball bearing and does it
work? A brass bush will be considerably less expensive than an £80 ball bearing. Here`s hoping for a
solution to get the bike back on its wheels on the road.
#3745 You say that tack welding buggers up both parts. Here's another thought: With an OD size of 3.8
inches, the bearing/bore interface has about 12" of circumference. A tack weld has about 1/4" of length,
so four of them will use up about one of the twelve inches. Given that later removal of the bearing likely
would destroy that bearing, OR the chainwheel, and given that the chainwheel sprocket is normally
subject to damage from wear, what do you have to lose by welding? If not welding, how about a two
part epoxy such as JB Weld? I was told by Ed Gilkison that the OD of the bearing was tapered such
that when the smaller diameter was pressed in to the chainwheel it would tighten up.
#3750 Between the chainwheel and the bearing, I'd say that if one is worn, it is more likely to be the
chainweel, as it is softer. As you probably know, if you suspect there is a taper, try fitting first from one
side, then from the other. The taper would be more likely to be on the chainwheel, if there is one, but in
mechanics no possibility can be neglected.
#3752 Check for adequate clearance between the ID of the inner and the OD of the prongs of the back
plate - I tell you if it is too tight here the bearing will work out of the chainwheel no matter how good a fit
on the OD. Don't know if Dai has the factory tolerances but the inner needs to be a sloppy fit (excuse
the technical jargon) on the back plate. As to the big bush in lieu of expensive ball bearing option, I
suggest you find a friend with a late model machine and measure up - I loaned the chainwheel and
backplate from my 69 Clubman to a friend last year and for about AUD$25 he had a bronze sleeve for
the backplate and a big bush for the chainwheel manufactured to the same sort of tolerance as my
partly worn example. When I got the bits back I threw the clutch together and the original 1969 big bush
is still there and working fine. I'm not aware of it causing problems after the factory changed from
expensive ball bearing to cheap bush - the only time it does any work is when the clutch is disengaged
anyway. I know of another 69 Clubman that has never had the clutch apart, and it would certainly have
the same clutch parts as mine, being only one engine no. apart.
L #3927 My 1970 Venom Clubman clutch slips, so I need to adjust it. I made the proper tool, but
the inner and outer race both turn together when I rotate the rear wheel. The manual describes a
technique where you place the trans in gear, and rotate the wheel the opposite way. This seems to take
advantage of differing rotation speeds of the two parts. My question is this: How fast does the clutch
adjust with this technique? In other words, using this alternative technique, what is the ratio of wheel
turns to the standard technique (when it works). Also, my bike only has about 200 miles on the clock
from new. Should I pull the clutch apart to see what's going on? (I'm not anxious to, but will if
recommended.)
#3928 Initially, depending on the degree of mal-adjustment, you may need to engage top gear and with
engine turned against compression a complete rotation or two of the rear wheel may be required. (for
safety sake, remove the high tension lead from spark plug). After clutch has been properly adjusted,
some miles racked up, and you are making a new adjustment to correct for settling, etc., 1/8 - 1/6 of a
turn of the rear wheel will be sufficient find that I must turn the wheel forcibly and swiftly to move the
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