love mine. the two bikes are relatively at odds with each other bar the high possible mileage, use of plentiful alloy and grease nipples, and racing heritage of the companies (6 outright ISDT world cup trophies in the 60's isn't really to be sneezed at). friend once asked which i'll prefer once lindie is done, but i think i can share love equally between the "bentley of bikes" and (not in a derogatory way) the moskvitch/trabant.
hello from a state of disassembly.
- Thread starter lindie
- Start date
Trabbies
I drove one once, from Buckinghamshire to Wigtonshire, about 300 miles. It was extremely cramped (and I ain't big) but was really nice to drive. Elegant engineering, given the low cost. Particularly satisfying was finding that it tracked like a Mini, and that in Buckinghamshire lanes I could leave a VW Golf in the dust.
I drove one once, from Buckinghamshire to Wigtonshire, about 300 miles. It was extremely cramped (and I ain't big) but was really nice to drive. Elegant engineering, given the low cost. Particularly satisfying was finding that it tracked like a Mini, and that in Buckinghamshire lanes I could leave a VW Golf in the dust.
once again a weekend with the bike has passed and i'm confused a little more. i pulled the clutch cover off this evening only to be shocked by an unexpected sight. where i was figuring on seeing the normal servo clutch and it's workings, something was off with my picture. first sign was only three bolts, then the multiplate appearance of the mechanism, and finally the fact i'd seen this shape before in magazines.
on nortons.
a quick google shows it as being a pre 1957 norton clutch or at least parts thereof. and it works. anyone ever seen this sort of conversion performed? overall, if the dominator of the day and possibly the manx(?) were able to put their power to ground with a clutch of this format then maybe it should stand up to a sensibly ridden stevenage twin. the more i get into this bike the more i wish i had an inter celestial phone to ask my deceased uncle of it's oddities and get some advice on a few matters. perhaps i'll see if i can rent a ouija board.
on nortons.
a quick google shows it as being a pre 1957 norton clutch or at least parts thereof. and it works. anyone ever seen this sort of conversion performed? overall, if the dominator of the day and possibly the manx(?) were able to put their power to ground with a clutch of this format then maybe it should stand up to a sensibly ridden stevenage twin. the more i get into this bike the more i wish i had an inter celestial phone to ask my deceased uncle of it's oddities and get some advice on a few matters. perhaps i'll see if i can rent a ouija board.
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Yo Lindie! Yes that is a Norton clutch and I used to race and sprint with one for which it was perfectly OK. However, I also used one on the road and it does not like getting hot in traffic. The plates swell up and you lose the adjustment on the clutch lever. London traffic, even 40 years ago, was a problem so it will depend upon where and when you aim to use your bike as to whether you should stick with it. Good luck 
Non-Vincent clutches
My bike had a "Dolphin Motors Conversion" which was a Triumph clutch. Unfortunately fitting it meant milling away the clutch housing, so my options are to run wet, or wet, which means a return to original isn't possible. Or at least requires far more work than I'm prepared to put in for something no one can see....
The 'umph clutch wasn't really up to it, even with an extra plate and new springs. I suspect it wasn't that it couldn't take the power: it couldn't take the torque! However, thanks to an Oz product called new miracle NealVidean, I now have a Shadow that goes like a Shadow, with a clutch that I've stopped thinking about. The only problem I ever had with the PV3 was that it was a ****** to free off before starting, and that seems now to have cured itself.
My bike had a "Dolphin Motors Conversion" which was a Triumph clutch. Unfortunately fitting it meant milling away the clutch housing, so my options are to run wet, or wet, which means a return to original isn't possible. Or at least requires far more work than I'm prepared to put in for something no one can see....
The 'umph clutch wasn't really up to it, even with an extra plate and new springs. I suspect it wasn't that it couldn't take the power: it couldn't take the torque! However, thanks to an Oz product called new miracle NealVidean, I now have a Shadow that goes like a Shadow, with a clutch that I've stopped thinking about. The only problem I ever had with the PV3 was that it was a ****** to free off before starting, and that seems now to have cured itself.
mines still dry, in spite of a primary case full of oil and being stored on its side for the better part of a decade, so evidently my seals mustn't be too far gone. someone has drilled either a vent or drain hole in the bottom of the cover plate too so perhaps this was necessary or just a precaution at the time. i like the fact that the unloading pushrod is able to lift via a large flat surface whereby at least it'll release and apply in a square fashion independent of whether the springs are alternate tensions.
This is a reply to lindie who has sent me a private message. However, as I understand it, the aim of this Forum is the open exchange of information so I am replying here in case the answer is of use to others than just lindie himself. First I will copy lindie's request for information below and then answer his points.
g'day. name is glen and if you've a minute might i pick your brain please.
the norton clutch looks robust enough and grips and releases well enough for starting purposes so should be alright for riding, how did such conversions come about, and was this one common?
were your's self done or was there some sort of kit at the time?
how was everything held together (ie the clutch drum to the primary sprocket and the hub to some form of splining?
did they all have friction inserts of brass/asbestos or were there cork types as well?
the hub to spline of mine looks distinctly home made'ish with the shoe carrying ends of part no. C3 lopped off, three holes drilled and tapped into it at 120 degree spacings, the spring bolt retaining studs screwed through the hub into them, then some braze applied to the two and over the studs to act as a thread lock i expect. the other half in which the plates reside is as was shown in the last picture. i can see what looks to be the centre of part C21 or maybe C13 (something there with 9 holes in the same disposition anyway) but it is mounted inboard of the splined hub in contrast to normal vincent positioning.
sorry to hit you with all these, but till i get it apart (which i don't have much desire as it looks to function ok) i'm in the dark as to how they tied it all together.
thank you for your time, glen.
Reply:- Hi Glen, as far as I know there were no kits available and so I made mine up from parts bought from various breakers or bits I had lying around. There were two types of outer plate. The pressed steel one which you have and which I still have on my sprint engine and a cast aluminium one which is still on my Knight. The cast ally one would be my choice for any conversion but I had to use what was available. The hollow splined shaft part of the C3, together with a part of the ears was retained and the top of the ears machined off to give as much of a circle as was possible and this was sif-bronze welded into the centre of the Norton clutch. A piece of steel was machined up to give the shape of the back of a standard Vincent clutch drum complete with countersunk holes for the screws which fasten the drum to the sprocket. Lightening holes were machined in the back of this circular plate as in some of the early Black Lightnings. but as this was steel and not cast iron there is no danger of the whole thing exploding. This plate was then sif-bronzed into the outer part of the Norton clutch which takes the outer ears of the clutch plates. By means of some careful fiddling about I was able to get five plates into the clutch. The C20 nut and retaining spring were used. Why was this done? because the Vincent clutch does not free easily enough at high revs to allow rapid gear changes when racing or sprinting. I have no idea how much power the engines produced. The production class sprinter did 135mph at the end of a standing start half mile and best quarter mile time was 13.06 seconds so it was not slow. This was in a state whereby it could be ridden to meetings but it did not have a rear stand or front stands. Fuel was five star. In those days I weighed about 150 lbs, about 68 kgs. The Black Knight was my main road transport and its engine was more or less standard. I did a camping trip to the South of France from the UK and I took it to South Africa when I worked there and it did several trips from Pretoria to Durban and back as well as doing a sprint near to Johannesburg (?Kyalami). As far as I am concerned this clutch did all that I wanted but I do remember having to be fastidious to slip into neutral in heavy traffic or I would lose clutch adjustment as the plates heated up. My memory is that I always use friction plates with stuck on friction pads rather than cork inserts. If I understand correctly your modified C3 is bolted to the back of a Norton clutch whereas mine was sif-bronzed. I would want to know what was used or that the system has been proven with a lot of use before trusting that too much. As an aside to all this and for those who still worry about getting oil into the standard Vincent clutch; if you will only machine a 'v' countersink or a 'square' section cut out at the rear of the hollow splined shaft on the C3 you can then insert an 'o' ring to act as a seal. This totally stops oil moving along the splines and does away of the nonsense of putting sealing compound on to the splines or using non effective seals behind the retaining nut C20. Stop the oil getting in, not getting out. I hope this is of use. G'day.
g'day. name is glen and if you've a minute might i pick your brain please.
the norton clutch looks robust enough and grips and releases well enough for starting purposes so should be alright for riding, how did such conversions come about, and was this one common?
were your's self done or was there some sort of kit at the time?
how was everything held together (ie the clutch drum to the primary sprocket and the hub to some form of splining?
did they all have friction inserts of brass/asbestos or were there cork types as well?
the hub to spline of mine looks distinctly home made'ish with the shoe carrying ends of part no. C3 lopped off, three holes drilled and tapped into it at 120 degree spacings, the spring bolt retaining studs screwed through the hub into them, then some braze applied to the two and over the studs to act as a thread lock i expect. the other half in which the plates reside is as was shown in the last picture. i can see what looks to be the centre of part C21 or maybe C13 (something there with 9 holes in the same disposition anyway) but it is mounted inboard of the splined hub in contrast to normal vincent positioning.
sorry to hit you with all these, but till i get it apart (which i don't have much desire as it looks to function ok) i'm in the dark as to how they tied it all together.
thank you for your time, glen.
Reply:- Hi Glen, as far as I know there were no kits available and so I made mine up from parts bought from various breakers or bits I had lying around. There were two types of outer plate. The pressed steel one which you have and which I still have on my sprint engine and a cast aluminium one which is still on my Knight. The cast ally one would be my choice for any conversion but I had to use what was available. The hollow splined shaft part of the C3, together with a part of the ears was retained and the top of the ears machined off to give as much of a circle as was possible and this was sif-bronze welded into the centre of the Norton clutch. A piece of steel was machined up to give the shape of the back of a standard Vincent clutch drum complete with countersunk holes for the screws which fasten the drum to the sprocket. Lightening holes were machined in the back of this circular plate as in some of the early Black Lightnings. but as this was steel and not cast iron there is no danger of the whole thing exploding. This plate was then sif-bronzed into the outer part of the Norton clutch which takes the outer ears of the clutch plates. By means of some careful fiddling about I was able to get five plates into the clutch. The C20 nut and retaining spring were used. Why was this done? because the Vincent clutch does not free easily enough at high revs to allow rapid gear changes when racing or sprinting. I have no idea how much power the engines produced. The production class sprinter did 135mph at the end of a standing start half mile and best quarter mile time was 13.06 seconds so it was not slow. This was in a state whereby it could be ridden to meetings but it did not have a rear stand or front stands. Fuel was five star. In those days I weighed about 150 lbs, about 68 kgs. The Black Knight was my main road transport and its engine was more or less standard. I did a camping trip to the South of France from the UK and I took it to South Africa when I worked there and it did several trips from Pretoria to Durban and back as well as doing a sprint near to Johannesburg (?Kyalami). As far as I am concerned this clutch did all that I wanted but I do remember having to be fastidious to slip into neutral in heavy traffic or I would lose clutch adjustment as the plates heated up. My memory is that I always use friction plates with stuck on friction pads rather than cork inserts. If I understand correctly your modified C3 is bolted to the back of a Norton clutch whereas mine was sif-bronzed. I would want to know what was used or that the system has been proven with a lot of use before trusting that too much. As an aside to all this and for those who still worry about getting oil into the standard Vincent clutch; if you will only machine a 'v' countersink or a 'square' section cut out at the rear of the hollow splined shaft on the C3 you can then insert an 'o' ring to act as a seal. This totally stops oil moving along the splines and does away of the nonsense of putting sealing compound on to the splines or using non effective seals behind the retaining nut C20. Stop the oil getting in, not getting out. I hope this is of use. G'day.
thanks for the answer matey. the bolts are through into the c3 too but as you'll see in a sec she copped some brazing too.mine had the little spring fitted too though it was removed for the pics.
i take it the three cutouts in the norton hub were for a cush drive made superfluous by the ESA on the vincent therefore meaning the welds and bolts could be solidly fixed eliminating the floating plate and rollers needed for the rubber damped norton application.
would you say the c21 plate would in this instance be the 9 hole part in the previous picture? i assume it's had it's spring tube holes enlarged to a set depth to allow the large screws fitted to retain it to the primary sprocket. can only imagine it's also been welded to the norton basket. might find out if i get round to plucking the primary case for polishing one day but no rush.
again, many thanks for the enlightenment, glen.
i take it the three cutouts in the norton hub were for a cush drive made superfluous by the ESA on the vincent therefore meaning the welds and bolts could be solidly fixed eliminating the floating plate and rollers needed for the rubber damped norton application.
would you say the c21 plate would in this instance be the 9 hole part in the previous picture? i assume it's had it's spring tube holes enlarged to a set depth to allow the large screws fitted to retain it to the primary sprocket. can only imagine it's also been welded to the norton basket. might find out if i get round to plucking the primary case for polishing one day but no rush.
again, many thanks for the enlightenment, glen.
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Hi lindie. I cannot see any sign of the original C21 on your pictures and it would not be a good idea to weld it as it is meant to be hardened. Only you can tell from an inspection of the parts whether there is anything that looks as thought C21 was used. It certainly did not come into use with my modifications.