BSA A10 46
When Rob Smith bought a café racer A10 more than half a century ago, it wasn’t quite the Rocket Gold Star which the seller had described. Since then it’s been reincarnated several times and is still going strong…
When Rob Smith bought a café racer A10 more than half a century ago, it wasn’t quite the Rocket Gold Star which the seller had described. Since then it’s been reincarnated several times and is still going strong…
Over the past 50 years, my A10 has changed appearance so much that some members at the Worcester Auto-cycle Club have wondered if it was more than one bike which shared a registration. Obviously, these allegations are totally unfounded! But the BSA 650 has gone through many incarnations since first acquired in 1968, when it was swapped for a 250 Greeves Challenger.
Although it was re-registered in August 1967 as a Rocket Gold Star, I discovered that the A10 was actually a 1958 Super Rocket engine housed in a 1958 Goldie frame. It was presented in café racer trim, complete with an 8” front brake converted to a twin-leader, Taylor Dow Superleggera alloy top yoke, clip-on bars and rearsets. Its crowning glory was a glassfibre combined petrol and oil tank which, I soon discovered, could create more than a little discomfort to certain sensitive parts due to the hot lubricant which lived in its rear section…
Its previous owner was unable to start the A10 when I bought it, because of a ‘broken oil pipe’. Caveat emptor: I entered a very expensive learning curve and the truth is that I’m still learning. After fitting new oil pipes, the motor would only run on the one pot. So I rode my 325cc singlecylinder A5 to a gentleman who allegedly ‘knew all about motorbikes’. I was so impressed with his immediate diagnosis (‘It’s your cam followers, mate’) that I left the BSA with him. When I returned the following week, eager to find out what progress had been made, I discovered the engine had been removed to reveal the exposed frame. There, to my horror, I saw a pronounced ‘buckled’ lower frame tube. He ‘who knew all’ suggested previous accident damage…
While searching for a replacement frame, I found that my frame was numbered as a CB32, effectively meaning the bike was a ‘Gold Star Rocket’ and not an RGS. The ‘bent frame’ was actually an original feature, designed to clear the oil pump housing of the original single
cylinder engine. My investigations revealed that this conversion was possibly first instigated by Gold Star specialist Eddie Dow, who, it is said, encouraged the BSA factory to produce the Rocket Gold Star.
Several weeks passed, and the same number of ten pound notes were handed over. My now dismantled engine gathered dead flies and fag ash lay on the ‘expert’s’ cluttered workbench. When asked how much longer I would have to wait before it would be running again, he merely shrugged his shoulders, replying ‘When I have time, mate.’
I could wait no longer. The dismantled engine was transported home in two trips, carried in a wooden box which was lashed to the back of a Mobylette moped. The rolling chassis was pushed, mostly uphill. I received some bewildered looks from folks on the final short, downhill section, with me silently coasting by on this café racer minus its engine…
The motor was re-assembled with a little help from my friends, complete with those extremely expensive new cam followers. I savoured the thought of riding a full-blown 650 for the very first time and gave the kickstart a hefty swing. Yes! It ran! On one cylinder.
An elderly neighbour, observing my unsuccessful efforts, recommended a reconditioned magneto. The troublesome K2F was sent off to Lucas for a complete overhaul and what returned was not my old, refreshed mag, but a brand new K2FC competition unit. That did the trick, and both plugs finally did what they were intended to do.
Another problem became rapidly apparent: vibration. As this was my first fourstroke bike, I wasn’t sure if the amount being experienced was the norm. Other riders suggested the crank was out of balance. There was a series of ads in the weekly bike papers offering dynamic crank balancing by none other than the Repco Brabham F1 race team. I worked near their headquarters so decided to place the A10’s crank, conrods and pistons in their hands. A few of weeks later, they had been reinstalled.
On start up, I naïvely expected a turbinesmooth engine. It was not to be. There was some improvement but not as much as
I’d hoped. Travelling further up that costly learning curve, I discovered that the headsteady mounting location differed on the Goldie frame to its position on the A10. A modified head-steady improved things significantly.
1970 rolled around: Jean and I were married, and where better to spend our honeymoon than the idyllic Isle of Man? By coincidence the TT organisers had chosen that very same week... The A10 was the obvious choice, although there was a problem. We needed to transport a huge kitbag containing my spouse’s essentials. This was resolved by installing a section of Dexion racking on the back. Despite the added airbrake, we arrived at Liverpool in good time without problem. Then a grinning dockworker pumped out my petrol tank before we could board the ferry!
We spent that week touring the island in glorious weather. On our return, that painful dual-function glassfibre tank was replaced with a five-gallon alloy version and a conventional oil tank installed in its rightful position. Nine months later, our first son was born. A secondhand child-adult Palma sidecar was purchased and fitted by its former keeper, who gave me a brief lesson on the techniques required to ride a motorcycle combination.
The snag was that my A10 still retained its clip-on bars and rear-sets. That ride home was the most terrifying experience I have ever encountered on a motorbike. Things improved with a footrest and handlebar change, followed by a visit to Watsonian to buy a new hood. There I met an amazing character called Buster Heath, who had an artificial leg and rode a 1000 Vincent welded to a Watsonian chassis with a GP body. After telling him of the A10’s wayward handling, he rectified the misalignment problems for me.
This improved the machine’s cornering capabilities and my wife’s passenger confidence, to the point where I could transport mother and baby son from the maternity hospital – to the obvious disapproval of the matron!
Later, an increasingly loud tapping noise arose from the engine and signalled that the 10.1 pistons (installed when the A10 was a solo) were endeavouring to lift their cylinders off the crankcase. Our journey home was completed with feet pressed firmly on the cylinder head. Those high-comp pistons were replaced with a pair of the 8.1 variety, with no further problems.
The taming of the A10 was completed by fitting 16” alloy rims with Dunlop racing tyres. This made for exhilarating journeys, although lowering the outfit did raise a particular problem when driving through water. We were fording a stream just for fun, much to the delight of our son but not that of my wife! Mid-way, we lost traction on the slippery, moss-swathed stones. This demanded the removal of socks and boots and dismounting to push the combination out from the slowrunning stream, operating the throttle and clutch simultaneously.
On dry land, a torrent of water escaped from the underside of the sidecar. It was less than watertight and I wasn’t alone in having wet feet – a fact which was pointed out to me in no uncertain terms by the other half!
When I became a father of two, the time had arrived to release the A10 from the Palma and it was placed into retirement, leaning against a wall at the back of the house. A Plastic Pig took its place and I was without two-wheeled transport for some time.
Eventually, as and when funds permitted, my old A10 was
gradually brought back into action. The first job was to return it to 19” wheels. I could only afford to have the rear rebuilt, so the front wheel came from a Honda 450 Black Bomber, slotted into a pair of Metal Profiles forks. Although frames can be distorted during sidecar usage, fortunately the BSA pre-unit chassis was such a sturdy structure that it suffered no such ill effects. With a lot of overtime, I was able to make the cycle conversion complete. A two-gallon Catalinatype Gold Star tank was purchased from Len Onslow, later followed by a four-gallon variety, then a correct seat with mudguards and brackets supplied by John Gleed.
Next came the engine. That was dealt with by Steve (EX-SRM) Mcfarlane who rebuilt the bottom end in 1984. The top end was refurbished in 1997, again by SRM, revitalising the engine with plus-80 pistons. Fitting an Ariel Huntmaster rocker box gave improved access to tappets and pushrods, much superior to that of the BSA with its multiple fasteners, compared to the Ariel’s two. Other modifications included stainless spokes laced into Dunlop alloy rims, a beltdriven 12V dynamo, and various clutch types were tested, ranging from 6, 4 and 3 springs. I finally settled for the excellent Phil Pearson version.
I fitted a Kawasaki front drum brake from a 500 triple and a Japanese carb, but wasn’t impressed with either so reverted to the original 2ls 8-inch brake and Amal. Finally, all the fasteners were replaced with stainless. This should have been the end of these chronicles…
Well, not quite.
In 2001, on a hot spring afternoon, I took
the opportunity for a steady ride through Worcestershire’s leafy back roads. I returned on the bypass at a cooling 60mph and passed a Golf GTI. Presumably miffed at being overtaken by an antique motorbike, he passed me and cut back in with some vigour. With the Oriental front stopper fitted at that time, there was no guarantee I could come to a halt quickly enough and I was more than a little peeved. A crimson mist arose and the 60mph breeze increased to a considerable draft…
Suddenly the power from the motor dropped. I pulled in the clutch and the engine seized. We were about 500 yards from the highest point of the dual carriageway. What to do? I had breakdown recovery but no phone in sight. Should I turn around and freewheel downhill, against the oncoming traffic to the junction? Or push to the top and attempt a restart down the other side?
As my first thought was almost certainly illegal, I chose an attempt on the summit. By the time I got to the top I was positively glowing. We picked up momentum down the other side, engaged second gear and dropped the clutch. The back wheel locked immediately. This was no piston seizure!
A long, hot trek home began. On arrival back at HQ, my first thought was to throw the A10 back against the wall and ignore it. But after a cold beer and a shower, the tools came out. By that evening the motor was removed and dismantled. The crankshaft was held firm by the timing-side plain bearing. There had been plenty of fresh oil in the tank, and the pump appeared to be in good order, but there was shrapnel in the bottom of the crankcase, possibly the remains of the driveside main bearing shim?
The options were a cheap fix or a total engine rebuild. Hopefully, I have plenty of riding years remaining, so chose to completely refresh the motor from head to crank. The cost of this virtually new engine was much the same as the purchase price of our house in 1971…
Twenty trouble-free years have elapsed since that engine rebuild, with just over 16,000 miles clocked. The old A10 now shares a stable with a 1959 Golden Flash. They both start easily, possibly due to reconditioned magnetos and new carburettors. However, there are fundamental differences. The Gold Star Rocket is clearly quicker off the mark, with its hotter camshaft, larger valves and slight increase in capacity. The Gold Star brakes are easier to maintain, being truly QD, and more responsive with twin leader front and rod-operated rear compared to the full width hubs and spongy cable rear brake on the standard Flash.
The Rocket really benefits from the Pearson clutch; no fear of slippage and I know that neutral can be easily selected. It can be a lottery on the Flash with the six-spring clutch. Both A10s handle well and cruise comfortably at legal limits – above those speeds then vibes will make themselves known on both. However, that is rarely a problem.
Fellow club members have questioned my sanity over the years at spending such an amount of money on an old bike. But any new superbike would depreciate just as much. It’s remarkable that my Rocket’s engine and frame left Small Heath in the same year but were destined to go their separate ways. They were united after just eight years and have remained together for over half a century. This motorcycle has done everything I have asked of it – and much more at times.
What remains on my shopping list? Maybe a return to Steve Mcfarlane for an electric starter!