BSA 1960 Spitfire Scrambler Restoration.

Started by Superarnie, 27 Nov, 2022, 14:31

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Superarnie

Hi to you all.
By way of introduction, I am the proud owner of an original BSA 1960 Spitfire Scrambler. I understand the frame and engine numbers are correct and as it left the factory. I purchased it last year and it has, during the course of its 62-year life, been converted to a road going bike and now bears little resemblance to its original identity. I am in the process of doing a complete nut and bolt restoration and will return it back to stock specification (but maybe with a few of my own preferences into the mix) and have opened up this topic/thread to show you all the progress along the way, which I hope you will enjoy and find interesting, but also in the hope that I may elicit information from you that may help me with some of the more technical issues. So please do contribute.

I'm hoping that I have managed to attach an image(s) of the bike that shows the state when I first bought it. You may notice that it has been fitted with awful ape hangers, the front and rear mudguards (fenders) are incorrect. It has been fitted with road style exhaust pipes, the tank is not as original, and a previous owner has welded passenger foot pegs to the swinging arm - of all places! There are many other nonstock items, but I'm going to set about striping it all down and start afresh!

Not sure if the image(s) will attach in the correct place but here goes.


Superarnie

OK, those images seem to have attached alright.

So I set about stripping everything off the bike and making an assessment of what I had. Front and rear wheels were buckled, the carb was an Amal monoblock but was not the one specific to this machine. The rear shock absorbers were not the correct spec. It had a speedo and ammeter fitted- neither will be kept. The gearbox was a standard 'STD' spec - not correct for this bike, but I may keep it, as I will be using the bike on the road mainly. The handlebars- no surprise here, will be going. The petrol (gas) tank isn't right and will need further investigation. Otherwise the engine looks ok, it turns over fine, but it too will be coming apart and refurbed.

Here's a couple of images of the strip down.




Spaceman

An interesting project but, presumably, you are going to have to fit lights and silencers to it to use it on the road?

Superarnie

Hi Spaceman -
Thanks for your interest - lights and horn yes - not sure where I stand with the silencer issue. Might need to seek advice on that one. I'd rather not but may have to.
Due to the age of this bike, it will be exempt from MOT requirements, so not sure who will judge it to be too loud? Can you advise?

Superarnie

Here's a couple of images of what I'm aiming for as an end result.

Superarnie

#5
Once stripped, the frame was found to be very straight. The only cause for concern was the lower left side tube where the kickstand was mounted. That section was torn up and had to be repaired and strengthened. The passenger foot peg lugs were ground off the swinging arm, it was then filed and polished smooth. The frame and swinging arm were then sent to the powder coaters.

Superarnie

Whilst the frame was away being painted, I striped the petrol (gas) tank down and was pleasantly surprised to find that it was an original tank that had been body filled and over painted during its life. The original paint colour could be seen on the underside. There were a few dents and bruises but I'm sure I can do something with it!

Superarnie

I stripped both wheels down and sent the hubs to a wheel builder in Norfolk. The hubs were cleaned and powder coated. The front hub was mounted in a 19 inch flanged alloy wheel rim and the rear was mounted in an 18 inch flanged alloy rim. I know the rear wheel was originally a 19 inch but I like the slightly 'squat' look of the 18's and there is a greater choice of tyres for the 18 inch. I also stripped down the front forks. Both fork tubes were bent and therefore replaced. The fork legs were powder coated and I reassembled with new bushes, seals, gators etc. I have put a slightly wider 19 inch tyre on the front; 3.5 instead of 3.25 and on the rear I have put a Pirelli 18 inch 110/100/18 knobbly. However, since I have fitted it, I think it is slightly too wide and will rub against the chain guard, so I've since bought a 100/100/18 instead; it hasn't yet been mounted on the rim as I'm hoping I might be able to make the 110 fit somehow. The frame is now back from the powder coaters and reassembly can begin! I have fitted a correct handlebar and replaced the headstock bearings. I have also fitted a pair of original Girling rear shocks. Here's some images.

Superarnie

OK, so we've now got a rolling chassis!

Next I bought a fully reconditioned Standard (STD) gearbox off the internet. I will keep my eye open for an original 'SC' spec gearbox, but I'm in no urgent need of that just yet.

Could anyone suggest a good sprocket combination (primary/clutch/gearbox/rear wheel) for this set-up? Aiming for good road manners really I suppose.

Here's a couple of images of the gearbox.

Superarnie

The engine is stripped down. The cases are in good order and have been bead blasted. The crankshaft is also in fine condition and appears to have had a 1st grind. The end play will be DTI'd before reassembly and shimmed if necessary.  I've bought new big end shells (10 thou under), new main bearing, the crank bush on timing side seems to be fine. I've bought a new sludge trap and conrod bolts and new small end bushes. The barrel is in excellent condition and will be honed. The pistons are excellent forged items and 60 thou oversize. I will replace the rings. I plan to start the engine work/rebuild before Christmas. I plan to fit electronic ignition and my mind is thinking about the Thor system. If anyone could advise on this system or an alternative product, I'd be grateful. I wanted to keep the dynamo looking stock - hence the Thor system.

That's all for now folks. Have a good day!

Superarnie

Forgot to mention; I have also sourced an original spec rear mudguard/fender. I have stoneguarded the underside and now fitted it.

That's really all now folks!!

EDDIE SIMPSON

after going to all the trouble of finding original period parts for your project why go for electronic ignition. a manual competition k2f would suit your project and run great when overhauled with new armature and remagnatised body. no dynamo required either.

Superarnie

Hi Eddie,
Thanks for your response. This is a reason I have posted my project on this forum, in order to seek advice along the way. I will listen and consider all advice before I make my final decision. From the research I have done so far, I hear equally good arguments for each option. I am airing towards the Thor electronic ignition route for now as I have read about its reliability and concealed installation thereby not detracting from an original look. I suppose also Eddie, that it would be fairly straight forward to put it back to stock.
Thanks again.

EDDIE SIMPSON

i have rebuilt 2 magnetos using paul wolf exchange armature and re magnatised body with excellent results. i believe he advertises new mag armatures on the internet.

Superarnie

Thanks Eddie. I've looked him up on the internet. He seems to have an excellent reputation. The dilemma I have is that I have read mixed views over the subject of retaining the old magneto/ points system or swapping to electronic ignition. Some good, some bad views with each. I put electronic ignition on an old 1972 Yamaha RT2 and never had a problem with it. It was a hidden system and the bike looked stock. It's the reason I am drawn to the Thorspark. From what I understand, the system trigger is concealed inside the cap of the magneto and you wouldn't know it was there. Once installed, you get a good strong spark with no points issues to worry about. My earlier post in this thread was to seek opinions from anyone who has fitted this system to advise if its as good as publicised. This may help to swing my decision one way or another.