Misc: Everything Else 1951 Black Shadow Restoration

craig

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PD20C3fit.jpg


My issue is only PD22 is installed in PD20......and I have a fit issue with inserting C3/2.

What concerns me also is the fit of PD24 into the PD20 sprocket.
and becoming an additional fit issue with C3/2,,,,never mind the lip seal.

I am about to get my digital mics out,,,,,,now how do you set the zero?
 
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Cyborg

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Buying bushings off the shelf can be a bit of a crap shoot.... too many variables. Faced with the same task of installing new bushings and a seal, this one will be of interest to me. The fact that there is a seal in between the bushings adds to the aggravation. Time saver lapping compound would be fine... except for the fact that the seal is there. Same goes for taking to to the guy with a Sunnen hone. If the bushings are oilite, which they should be, then skimming them on a lathe is an option, but an extremely sharp (appropriate) cutting tool must be used so the pores in the oilite aren’t smushed closed... and then there is the seal in there.
All the more fun because if the chain wheel drags, it’ll haunt you.
I suppose if one had lots of experience, all of the bits could be measured... calculate how much the bushings will shrink when installed and machine the bushings before installing them.

Edit... when installing bushings like the PD22 and C17 it is probably better to use a driver machined to fit into the bushing and then use an arbor press or hydraulic press just so it is easier to get the bushing started straight.... and continue straight. If it gets cocked at all, then the thin wall of the bushing will distort and cause a tight fit or drag on the shaft.
 
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Cyborg

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I thought Cyborg was taking the PEE ?,
But I would be lost without my Phone, Don't know why, In the old days we didn't have anything,
I remember thumbing a lift down the A1 at night, After I broke the T/side main shaft on my Goldie.
And when my Special stuffed a fibre pinion, After a long push, A couple of Lads got me and the Bike home ,
In a removal truck, Didn't want to wait 2 hours for the AA.
It's just all in the Head, Panic in my case !.
Only a short one... the latest tool catalog had a vernier caliper with Bluetooth. I assume that would come in handy for a production shop or QC in a wigit factory.
A friend of mine bought hearing aids and they have Bluetooth so he can listen to music on his iPhone or home stereo instead of his wife. Now there’s a sales feature for you Bill. I couldn’t get a caliper to talk to hearing aids, but one of the kids could.
I do like the digital readout. When turning something on the lathe...Zero it on the dimension you want and then every time you check progress, it tells you exactly how much is left to go. Not necessary, but convenient.
 

Bill Thomas

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There was a Telly prog' Where one brother told the other His phone would tell when the washing machine was finished !.
 

craig

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pd20c3fit-jpg.39740

PD22 seems to be supplied in oilite
PD24 is bronze with a swirl groove.

I chucked up C3/2 on a Norton cut off gearbox shaft and used 180 emery tape, then 320 tape.
Good fit up achieved.
 

timetraveller

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If you have the facilities modify the inside of the tube at the rear of the C3/2. The sealing methods on all models of Vincents to prevent oil migrating along the inside of this and the gearbox main shaft are inadequate. Machine a groove or taper on the inside of this to take an 'o' ring 1/8" or 3 mm section or something similar and put it there before you push the shoe carrier home. Ensure that there is at least five thou of nip on the 'o' ring before the shoe carrier is fully home. There is no need for sealing compound, an 'o' ring on the outer end or any other form of sealing. It just totally stops any oil migration and one ends up with a clutch which gets dusty, not oily.
 

Cyborg

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pd20c3fit-jpg.39740

PD22 seems to be supplied in oilite
PD24 is bronze with a swirl groove.

I chucked up C3/2 on a Norton cut off gearbox shaft and used 180 emery tape, then 320 tape.
Good fit up achieved.
I may end up doing something similar. Just had a look at the C3 that I thought I was going to use, and it has some scoring where the bushing runs. Gives me an option if the fit is too tight after the bushings are installed.
 

Robert Watson

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OR
On the inside end of PD 21 where it fits up against the bearing you can imagine the gap where the radius of the inner race of the bearing is abutted to PD 21 and just slip a 1/16 dia o ring in between there on assembly. We initially started by making new PD 21's and cutting the O ring groove internally before hardening and finish grinding, but the above method requires nothing except slipping the o ring in there.

Now I will pop my head down below the parapet as the precise engineering types lambast me for such a crude method as this is not how o rings are designed to be used!
 

greg brillus

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I don't know about that Robert, You need to be quite inventive to improve these bikes.......We all forget how quickly they built the first of them immediately post war, and no "O" rings back then either......oil leaks would have been common place, something modern folk don't like. I just use a thin smear of threebold on the inner face of the main shaft nut on final assembly.........This works just fine.......except if the bike has an issue with the main shaft nut coming loose all its own.......I believe this generally happens if the spline inside the C3 is worn and allows backlash on the mainshaft.........Not dissimilar to a gearbox out put sprocket that is loose on the output shaft........the nut will always come loose. That is why the mainshaft nuts need to be done up very tight, so no movement can cause any further wear and tear. So any reading this that have a problem with the clutch nut coming loose, you need to replace the C3 for one that has no play on the spline.
 

oexing

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What I could not see with this design is how the bushes get their lubrication. Yeah, you assemble with grease but no practical means to replace old grease. Poor lubrication in there will lead to a dragging clutch when you really want no friction for silent 1st gear selecting from stand still. So to achieve this most modern bikes got needle or roller bearings in the clutch gear or sprocket, oiled by gearbox oil or so.
The inner bush may get some oil from along the gear shaft, but after the o-ring the outer bush will be dry or starved . So when looking for a new place for a seal it would be better to have it at the outer end for leaving more oil to both bushes.
I made some mod in the sprocket for a needle bearing, the rest is a Kawasaki clutch , modified a lot plus adapters onto the Vincent gear shaft. No oil seal required with a semi wet clutch. But maybe one could get a needle bearing plus seal at the end to work with the standard clutch somehow ?

Vic
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