THE BIKE started life as a 1957 BSA 500 cc A7 Shooting Star and was flogged around South America before a mate gathered a container load of bikes and shipped them to Oz in ’91. It was a pretty sad looking machine when I took delivery, but I wasn’t too concerned as I bought it to road-race in the Classic (pre ’63) Senior (500 cc) Class.
Over the next 12 months, it was stripped down and items not needed for racing went in the bin, something I would regret 18 years later. Mudguards, tool-box, air filter, side and centre stands, kick starter, lights and generator removed. Other parts—oil tank, engine plates, rear sprocket, seat base—were replaced with duralumin. At the time I was living in the bush in a humpy with no electricity, so if I needed to drill a hole, it was a 50 km trip to a mate’s place in town.
The wheels were re-laced to Akront alloy rims with stainless steel spokes; the rear converted to 18 inch. The swing-arm rubber bushes were replaced with bronze; steering head bearings and fork bushes replaced.
The motor was warmed up. Larger A10 650 cc valves, lightened and polished rockers, alloy push rods, chamfered skirt pistons, polished rods, lightened crank, 357 cam, and a 32 mm Amal Concentric carb.
Its first race meeting was at the new Eastern Creek track; we were the first bikes to use it. Nothing like a film of oil over a new track. We finished last in most of the races. More horses needed. So over the next few years it gained electronic ignition, twin carb head (1954) with two 30 mm Amal Concentrics, roller timing-side main-bearing, and 13.5:1 compression by using T150 pistons and A10 rods shortened by 2.5 mm.
Now it was getting closer to the pointy-end with a few wins—but it all came at a price. With the higher compression, the barrels decided to part company with the cases. Quite a worrying sound at 100 mph down the straight! So I developed a through-bolt system to hold it all together. The four outside head bolts now go down to the cases. The next part to fail was the small journal crank. Not much I could do about that so I had to limit the revs to 7000.
Moderate success was achieved with wins at Amaroo Park, Oran Park, Wakefield Park, and Eastern Creek. Its best effort was being 1st placed in Division 2 at the ’97 NSW Championships at the Creek. ’98 saw its last race (read ‘blow up’) and it was retired under the house.
Fast forward ten years. I decided it deserved a second chance at life so I dragged it out from under the house. Ten years of crud and cobwebs. The plan was to put it on the road as a café racer—basically a racer with lights and mudguards.
It was stripped down and re-assembled with most of the moving parts replaced. Alloy guards, ace bars, speedo and lights were bought from all points of the globe, and a nice fibreglass tank from the UK. A pair of stainless steel coffee mugs were used to hide the underside of the speedo and tacho, and a sheet of stainless used to mount them. Two basic toggle switches handle lights and ignition. I made copies of the Eddie Dow fork dampers. A nice set of Mazzochi’s for the rear.
Once the roller was done, it was time for the motor—this time a A10 650 cc but not quite as high strung. The only parts off the old motor were the twin-carb head, cam, rocker box and ignition. New cases; large journal crank and rods; 10.5:1, forged, offset-pin pistons and thick flange barrels were assembled. The combustion chamber was modified to match the larger bore and tapered, alloy push-rods complete the motor. New inlet manifolds were made to match the two 30 mm Kehin flat-slide carbs.
The gearbox was rebuilt with new bushes and a kick starter installed. I still wanted an open primary but knew the chain would not hold up to road miles with no oil (okay for a few laps on the track). A belt and Norton type diaphragm clutch system was bought from Lytedrive as well as a belt drive for the generator. Silent and smooth with no slip or drag.
Soon it was ready. You won’t believe it, first kick it started for the first time in ten years. Oh man, it feels good. Out on the road there were a few teething problems, mostly electrical. The carbs were a pain to jet but were worth the effort.
Being a bit of a tight-arse, I thought I’d leave the old race tyres on until it was run in. WRONG. The front washed out and down we went. Lesson learnt, new Avon AM26 tyres fitted, and it handles like it’s on rails. Not bad for a 65-year-old. At 60 mph it’s only doing 3200 rpm and I have taken it to 7000 in top, you do the math!
There is still a few more mods to do, but at the moment, I’m just enjoying riding it again. Work in progress. Cheers.
Pics by Mark Yardley; words by Musky