Classic Motorcycles Variety In The World

Alternator Conversion For Ariel Square Four

Owners of the alloy-engine variants of the Ariel Square Four will be excited by the possibility of fitting a 300-Watt alternator. This conversion unit can be fitted to the standard bike without modification to the engine castings. Re-use of the original Lucas dynamo drive housing and chrome end cap mean that the bike will, at a glance, appear standard.

Square Fours are often converted to 12-Volt by simply changing the regulator and bulbs but this does little to help. More power is available from the dynamo but higher speeds are required before the initial cut in and this can actually make the situation worse. In addition to this, commutators and windings in the elderly Lucas units can disintegrate.

We have seen a number of dynamos where the segments in the commutator have started to move. This give unreliable performance as the uneven running surface gives poor contact with the brushes. This movement may also be the cause of fractured windings where they join the commutator.

Unfortunately little additional space is available over that occupied by the Lucas 3½ inch diameter dynamo. A permanent magnet alternator conversion that was available a few years ago gave reasonable results but unfortunately required some of the fins to be ground away on the back of the cylinder block.

After purchasing a number of modern Japanese bike alternators I came across a Nippon Denso unit which, although too big to fit as a complete unit, turned out to contain a petite 93mm stator. The Eureka moment came when it was discovered that there was room for the naked stator between the standard dynamo drive housing and the original dynamo mounting on the crankcase. Fill in the blank spaces and you have a working alternator!

Tight space and the requirement to attach an extension shaft to the Kawasaki rotor presented considerable difficulties. The coupling must not only be robust but allow the sealing arrangements, distributor drive and drive sprocket mounting of the original dynamo to be replicated. There is also a machined saddle cast on the rear of crankcase that provides a seating for the original dynamo. This represented a problem since the alternator body would need to be of a larger diameter than the 3½-inch Lucas dynamo.

Six months work solved these problems and a first prototype was finished and fitted to my Mk2 Ariel for testing. I was delighted with the results. Enough output was available to balance the headlight on full beam from a shade less than 30mph even extra tall solo gearing fitted. The surplus of power available also maintained a fully charged battery and kept the system voltage at a healthy 13.5-14.0 Volts. At this correct voltage the halogen headlamp bulb was able to provide excellent illumination, night time riding was now a joy and it was immensely pleasurable to burble around town in top gear rather than having to ride in third or even second in an attempt to keep the engine speed up.

Triumph Speed Twin

The Speed Twin 5T is a motorcycle that was made by Triumph at their Coventry factory. Edward Turner, Triumph’s Chief Designer and Managing Director, launched the Triumph Speed Twin at the 1937 National Motorcycle Show. It was a 500 cc OHV vertical twin in a lightweight frame and the first truly successful British twin, setting the standard for many twins to follow. After World War II the Speed Twin was responsible for the survival of Triumph - and every major British marque offered a 500 cc twin designed on similar lines to the Speed Twin.

Manufacturer:Triumph
Production:1938-1940 1947-1959
Engine:498 cc 360 degree parallel twin OHV four-stroke
Power:27 bhp @ 6,300 rpm
Transmission:4 speed / chain
Wheelbase:55 inches (140 cm)

Edward Turner’s Triumph twin was a major turning point for the British motorcycle industry, as although a 500 cc parallel twin of medium capacity was not revolutionary, the 5T Speed Twin model was lighter than many contemporary singles with significantly more power and torque. Early models were only available in 'Amaranth red' with hand painted gold pinstripes to set off the chrome. Initially the one piece iron cylinder was secured with six studs which led to weakness, so these were replaced by eight studs.The two cylinders were fed by a single Amal Type 6 carburettor and many features such as the transmission and clutch were straight from the Triumph single. Originally with girder forks, the sprung saddle was the only rear suspension as the Speed Twin had a rigid frame - also from the single cylinder production line. On the night of 14 November 1940 the majority of the city-centre of Coventry was destroyed by German bombs and the Triumph factory (which was working on an order of thousands of military specification 5T's) was completely wiped out, and all of Triumph's technical records, drawings and designs were destroyed.

Further development led to the 1959 model 5TA with a unit engine and gearbox construction and styling changes including the unpopular 'Bathtub' fairing which became more and more abbreviated as the model developed before disappearing altogether for the last year of production in 1966. The unit 500 engine continued development in the parallel Tiger 100 range ending with the Tiger Daytona models which ceased production in 1973.

Development
After the war the recovery of Triumph at Meriden was largely due to the Speed Twin, which was developed in 1946 with telescopic forks and optional sprung hub rear suspension. The headlamp and instrument area was tidied up in 1949 with the Turner-designed nacelle, a feature retained until the end of the model line. In 1953, the Speed Twin caused controversy among traditional British riders as the generator and magneto were replaced with a Lucas alternator and battery/coil ignition system.

Matchless G9

The Matchless G9 is a British motorcycle made by Associated Motorcycles at the former Matchless works in Plumstead, London. The G9 was finally discontinued when the 646 cc Matchless G12 (and AJS Model 31 replaced it in the autumn of 1958.

Manufacturer:Associated Motorcycles Plumstead, London
Production:1948–1958
Successor:G12
Engine:498 cc air cooled twin
Top speed:85 mph
Transmission:Four speed gearbox to chain final drive
Suspension:teledraulic forks, swinging arm rear
Brakes:drum brakes
Weight:395 pounds (179 kg) (dry)

Development
The Matchless G9 and corresponding AJS Model 20 were launched at the post war Earls Court motorcycle show in late 1948. Initially for export to the US, it was not until the late summer of 1949 that the first examples reached the home market. The styling was modern and the dual seat, megaphone silencers and bright chrome finish justified the name of Super Clubman for the matchless and Spring Twin for the AJS. The rest of the cycle parts were standard AMC, with the engine being housed in a pivoted fork frame with telescopic front forks. The basic design changed little over the course of the next few years, the most significant change being made in 1952 when a new Burman gearbox was adopted. In 1951, the rear suspension was upgraded to the Jampot unit, derided for its shape in the 28 September issue of the Motor Cycle magazine. In the same year minor changes included a new Lucas horn-push on the handlebar and a medallion badge in place of the previously used transfer. Front fork shuttle damping was also replaced with rod and damper-type. Progressively developed, the G9's twin-cylinder engine underwent a number of capacity increases, finally being discontinued when the 646cc Matchless G12 (and AJS Model 31 replaced it in the autumn of 1958.

Triumph 3TA

The 3TA was reasonably peppy and practical when it was introduced in 1957 (the Twenty-one name celebrates the Triumph Engineering Company's 21st birthday). Motor Cycling magazine reported that it was one of the fastest standard British 350 roadsters with an 'untiring zest' for high speed cruising, safe handling and remarkably economical fuel consumption. Not everyone liked it that much, however; 'the Twenty-one was a bland-looking motorcycle that came over as a diminished version of the traditional Triumph,' said Cyril Ayton, 'while falling short of presenting the integrated look of even the humblest scooter.'

The 18bhp 350 was capable of reaching 80mph - just - but in truth the fast rider was more likely to buy a 500. Dave Minton recalls that 'given a ruthless pilot, a hard-pressed Twenty-one would manage 75mph but any attempt to change direction hard and fast, or even hold the line along an undulating road, would cause the kind of nasty loss of stability that can only ever be a consequence of a weak frame.' So the 3TA tended to sell steadily thanks to its fuel economy (75mpg was perfectly possible), good weather protection and ease of maintenance. Triumph even sold it on those grounds as an 'easy to clean and clean-to-ride machine'. Perfect for the daily grind, then.

And that's just what happened to Geoff's 3TA. It got ground down over years of use and then neglect. Geoff and his brother took turns in owning it, and Geoff used it for commuting 50 miles each day in the mid-1970s. 'By 1977 it was worn out' says Geoff, 'and my brother had it back with the intention of restoring. Other things got in the way, so I had it back again in late 1982 but it continued rusting away for nearly six more years until restoration began in late 1988.

The Triumph gets used every year so has developed a few minor scuffs and dents. The only way to address these would be another cosmetic restoration, but I like it the way it is.

Since its restoration the 3TA has covered nearly 5000 miles. There were some teething troubles at the start; 'all the lights blew and the battery blew up when the lights were switched on. It was traced to faulty, original light switch.' Since then the 3TA has been '100% reliable. It really impresses me every year when it starts first kick after the winter lay-up - which can be eight months long!

Geoff's happiest moment with the 3TA came when it first took to the road after its initial restoration back in 1989. 'I could not get the smile off my face! It had been off the road since 1977 and it was wonderful to have it running again and looking like new.

The 3TA still attracts attention and won its class in the Shugborough Hall Transport Show last summer. Geoff reckons that this model is an ideal classic for anyone looking to try an old Triumph for the first time; 'don't hesitate, but don't expect it to go like a Bonneville!

1957 Matchless G11

The G11 was a development of AMC's 500cc twin; in late 1955 the Matchless G9 was stretched to produced the G11, while its counterpart AJS Model 20 became a Model 30. The new 600s shared a 593cc engine (72 x 72.8mm) running 7.5:1 compression, which output around 33bhp at 6800rpm.The 600s were something of a stop-gap model, replaced three years later in the AMC line-up by the 650 Model 31 and G12. As a result, the G11 is normally over-shadowed by its larger counterpart and many folk dismiss it. 'They were interim machine that do not fall into recognised capacity limits and do not fit our accepted thinking' is how one buyer's guide dealt with the 600s.

However, these days the affordable and reliable 600s shouldn't be discounted - FW reckons they're 'very pleasant to ride, with a generous spread of power and a distinctive style. They sound good, too. The 600 engine is fairly unstressed, proving little quicker but more flexible than its smaller stablemate.' When new, a G11 would reach just under the ton, and the tweaked sports version was the first sports-roadster bike to travel 100 miles around MIRA's test track within one hour. So, even 50 years later, a G11 should prove to be an entertaining ride for travellers in Provence.

The CBP G11 had indeed been rebuilt but it was suffering from a major crankcase oil leak. Much cross-Channel correspondence ensued, with Steve the Toaster shuttling parts down to Provence and helping to wield spanners, while FW provided advice and the chaps at AMC Classic Spares came up with the correct spare parts. It transpired that when the engine was last re-assembled someone had left out a critical gasket - that never helps if you're aiming for an oil-tight engine!

With the work complete, Neil could take the G11 for a shake-down ride - this was a moment of truth indeed because he'd not ridden a Matchless before, and he wanted to be sure that the bike was suitable for his holidaymaking customers.

'I had the first ride out -- some 25 miles cruising along at 40 to 55mph,' reported Neil immediately after the ride. 'This is the first time in two years the bike has been ridden and she ran beautifully. Lots of 'firsts' here as it was the first time I had ridden a Matchless… and my first impressions were very favourable. This is a machine which epitomises what classic motorcycling with CBP is all about. A relaxed riding speed, comfortable seating position, nice burble to the exhaust without being obtrusive, easy starter... and a great looking machine to boot!

'I thought the gearbox was smooth and felt positive with no unexpected neutrals. The clutch was light and progressive with no slip or drag. The handling was a little heavier than some of my other machines -- particularly the BSAs -- but it instilled immediate confidence. I've yet to scrape the footpegs but give me a few more miles…!

'It's a smooth engine with no vibration to speak of either through the footrests, seat or handlebars (but then I was taking it easy for running in). The engine appears to be oil tight so far: thank goodness, because that was the reason for the strip down!'

Neil finished the day by tightening down the cylinder head, then set off the next morning on the second leg of the shake down - a further 120 gentle miles. He discovered that, as with many AMC bikes of this period, the primary chaincase is prone to leaking (you can try to fix it until the cows come home, or chalk it up to be ing 'one of those things'!), and noticed that a couple of the tank mounting bolts and rubbers had worked loose with the vibration. Nothing unusual there - which is why it pays to clean down the bike after a decent ride and just check that nothing has worked itself free.

However, there was something strange going on with the rear wheel spindle. It caused a speedo hiccup and when Neil took the spindle out he 'found that the oil seal cup and washer were incorrectly assembled. Apparently this is a common mistake as in most rebuilds people logically fit the oil seal into the cup. This looks right but in fact is totally wrong! You learn something every day.

So what does Neil think of the Matchless 600, now that he's clocked up some more miles? 'The good news is that she always starts first or second kick... most important. And I've decided the handling is NOT 'heavy' as I first described. The bike feels sturdy and robust, and so the handling is predictable and reassuring. Choose what words one will, but it's unfair to say that it's heavy!

So the G11 passed its entrance exam, and is now a full time member of the Classic Bike Provence team. If you'd like to ride it - or any of the other classics, British or Japanese - in the CBP stable, you can contact their UK office on 0207 871 0471 or call 00 33 (0)442 287610 in France. There are plenty of tour dates remaining for this year - or you can try a classic taster, and get used to riding an old bike in sun-drenched splendour, without any traffic to distract you.