PROJECT: RICK’S NORVIN
Rick spent a lot of time working on other people’s bikes last year, so spent the festive season working on one of his. It turned out to be a nightmare after Christmas
Our man Mr Parkington fixes the speedo and dynamo of his Norton-vincent special
Many, many years ago I had a dream. In my dream I opened a barn door. Apparently it was my barn, and inside was a Norton-vincent special – dusty and in a bit of a state, needing a good sort out, clearly, but a Norvin all the same. I woke up, full of resolve. ‘Yeah, time I got on with the Norvin,’ I thought. Then it hit me. Dammit. It was just a dream.
Twenty-five years on and there is a Norvin in my shed – and yes, it’s dusty and needs sorting, but it’s not a dream. It’s more like a nightmare. You see, when I bought the bike I did a huge amount of work on it, but jobs left unfinished ultimately put it off the road.
The main worry was the tank leak. Fitting a standard Norton Dominator item involved cutting out and reshaping the bottom of the tank to clear the Vincent’s front carb and relocating the fuel tap. But my welding wasn’t fuel-tight and I’d had to resort to sealant, which had now failed.
Then there’s the charging system: there isn’t one. As bought, the bike had a dodgy alternator conversion tacked on to the primary chaincase, powering lights and coil ignition. I preferred the original system of magneto ignition and dynamo lights and soon built up and fitted a magneto, but the original Vincent dynamo mounting had been sawn off – and was in any case for a largediameter Miller unit, so fitting the smaller Lucas item I had was doubly complicated.
I machined the damaged crankcase flat and made up a shoe to mount the dynamo – similar to how it’s done on later Vincents – but the end fitting on the Lucas dynamo wouldn’t fit the Vincent casing and removing it would leave the dynamo bearing free to fall out. Besides, the Vincent dynamo sprocket runs jockey-style off the outside of the clutch and if anything goes wrong, the resulting debacle is likely to wreck the crankcases. I was scared, to be honest, and resorted to total loss battery lights.
Finally, the speedo has never worked. So what? Well, the bike’s tall gearing makes 30mph in top impossible. I have to guess, by ear, the revs at an approximate 30 in third, but speed cameras are unforgiving and near enough isn’t good enough. Recently I realised that the reason the speedo doesn’t work is that with the Vincent chain on the left, the Norton rear wheel is fitted back to front, so the speedo drive thinks the bike’s travelling backwards. I have a box of speedo drives, but all were clockwise – hardly surprising, as so are Smiths speedometers. So, do anti-clockwise ones exist?
These three problems don’t sound such a big deal as I write them down, but when you can’t come up with a plan and time is short, issues like these are surprisingly disabling. I mean, the tank alone drove me mad…
I’d originally Mig-welded it. It leaked, so I went over it with gas. It leaked. Finally brazing, but the joint still leaked. That’s only part of it. Even testing was fraught.
Everything is porous to a degree. You need pores smaller than the molecules of the fluid you want to contain. Petrol, for example, is more searching than water, so I had to use a (highly flammable) spirit for testing each time – and just a couple of pints was no good. It seemed OK until I filled up at a pump when the sheer weight of fuel found a leak the test process hadn’t revealed.
‘HOW DAFT AM I? WHEN I WAS 16, DAD FIXED A TINY HOLE IN THE TANK WITH SOLDER’
I tried brazing again last year, but my many failed efforts had left a thick joint, requiring increased heat that caused the sheet metal to crack on cooling. The heat burned and curled up the coating I’d used inside, making it impossible to re-seal. What a mess! Then I had a thought. What about solder? Braze would make a good base, so I polished up the surface with a Power File and, using a magnifier, found the tiny flaws and pinholes that were causing the leaks.
Cleanliness is always the key to success in soldering, so I warmed the area with a gas torch and repeatedly brushed the surface with Bakers Soldering Fluid. You can see the metal getting shinier as the surface oxidisation lifts. After this, the solder seemed very willing to pool on top of the braze – remember if it forms blobs and rolls about, it’s either not hot or clean enough (or both).
After all this time, no leaks! And should they reappear, I can easily do it again. How daft am I? When I was 16, as part of the restoration of my 650 Panther, dad fixed a tiny hole in the bottom of the tank with solder, splaying out the strands of a piece of copper wire as a mesh to bridge the hole.
Here’s how I conquered my other worries...