Classic Dirtbike

On top of the world

Occasional­ly in this sporting world of ours, a motorcycle becomes as famous as the rider. Two such machines will be awaiting inspection at The Classic Dirt Bike Show at Telford on February 17 and 18.

- Words: Tim Britton Pics: Mortons Archive

Are there two more iconic trials bikes than Sammy Miller’s Ariel and Gordon Jackson’s AJS?

There are a number of competitio­n machines which have taken on a life of their own and become equally as well known as the rider who used them to good effect. It’s arguable without the rider doing what they did these machines wouldn’t be so well known but the fact remains they were equal partners in creating a legendary pairing. While any number of machines could fill this spot we’re concentrat­ing on two trials bikes which pretty much rounded off the big bike era in the Sixties and the reason for this is they’re both going to be on display at the Classic Dirt Bike Show at Telford. These two machines are as close to the ultimate expression of what could have been, had their factories produced them for public sale yet neither machine was really suitable for anyone other than the riders who won on them.

Even without the accompanyi­ng pictures it’s probably easy to guess we’re talking about GOV 132 and 187 BLF – Sammy Miller’s Ariel and Gordon Jackson’s AJS.

Miller’s Ariel was the result of patient developmen­t over a number of years, developmen­t which began almost the second it was delivered to him and ultimately became more ‘Miller’ than ‘Ariel’, whereas Gordon Jackson’s AJS was produced for him by the comp shop at AMC. Gordon’s views and needs were taken in to account and the AJS built to his requiremen­ts. Both Miller and Jackson had riding styles unique to themselves and subsequent owners of the machines didn’t gel with the bikes as well as they did. It didn’t stop the world wanting replicas though. The problem was most of Miller’s major successes on the machine and the period when it became a legend happened after Ariel

ended four-stroke motorcycle production and AMC too were in the final throes when they built 187 BLF for Gordon to win the 1961 SSDT on.

The AJS was so special AMC turned down an order of 200 replicas of the bike, probably realising not everyone could do what Gordon could on such a machine… even Sammy Miller pronounced it unrideable yet Jackson won on it. In Ariel’s case their parent group – BSA – were not interested in allowing the Selly Oak marque the opportunit­y to produce replicas of Miller’s machine.

It is doubtful if an exact replica of each machine could have been produced and guaranteed for public sale as the level of hand-fitting on each bike couldn’t have been justified by the sales department. Miller did produce a kit for sale to help people update their Ariels and had at one time toyed with the idea of making replicas himself, but without the factory backing and knowing foreign shores were beckoning, the project was stalled. Ironically for the AJS, the final bikes to leave the factory in 1964 were pretty much a true replica of what Gordon had ridden.

Both motorcycle­s were the subject of contempora­ry magazine articles and the Ariel images are taken from a test conducted by The Motorcycle’s Peter Fraser – himself no slouch on a trials bike – and the AJS photos came from a shoot we did for CDB issue 19 when I also got the chance to ride 187 BLF. Though I’ve ridden many an Ariel HT5, I’ve not ridden GOV 132… yet… wonder if that’s a big enough hint?

Both bikes are at the show courtesy of the Sammy Miller Museum and are able to be inspected quite closely. The Ariel is probably the most highly developed of the two as Sammy himself was responsibl­e for most of the work and ideas behind it. By his own admission the early incarnatio­ns of GOV 132 followed more to standard Ariel practice than the later versions. Sammy had taken up employment with Ariel and was in their experiment­al department as well as the comp shop. As an employee he was often unsure just how far he could go when modifying the otherwise massive machine, recognisin­g the need to be seen riding what the company sold but also recognisin­g the need for the company product to be seen winning often meant he would park his machine out of sight if he’d done something as radical as fitting a high level exhaust system for instance.

His task in producing the lightest machine possible got off to a good start as the Ariel HT5 was already the lightest of the big bikes and of course Sammy had the run of the Ariel spares department so could mix and match components as he strove to gain ground clearance, lose height and reduce width and weight.

Lowering the height of the bike was accomplish­ed by chopping the bottom out of the fuel tank and sitting it further down on the top tube, this needed the oil feed to the rockers reversing to clear the underside of the tank but worked without being obvious and when allied to a lower seat – eventually to become a pad rather than saddle – gave the benefit of less restrictio­n when the need to foot arose.

As the frame was an all-welded rather than brazed lug and tube constructi­on, narrowing things at the mid-section involved cutting and welding, though this would still remain problemati­cal until post-1959 when Miller had a freer hand to design his own frame

and could dispense with the oil tank by using frame tubes to carry the lubricant.

Weight was saved by casting such things as fork yokes from alloy to replace the steel components, using hubs from the Ariel twostroke Leader/arrow range and drilling holes in as many parts as possible. To bring things in a little at the footrests an earlier gearbox mainshaft was used and the clutch brought inside the chaincase rather than being in its own compartmen­t – the clutch itself was a Manx Norton unit and already quite light before the drill got to it.

As with many such projects there are lots of details which aren’t obvious at first but add up to an effect and while alloy can replace steel and plastic can replace alloy nothing is lighter than a hole. Once the bulk of the big bits had been reduced, Sammy looked at removing things such as clamps and adjusters, preferring welded-on brackets for levers and brazed rings for the rear suspension springs to sit on. Bolts were as small as possible and from titanium wherever practical, wheel rims became alloy, chain size went down and so it went on.

So it was in this form Peter Fraser was invited to try the bike out as Sammy had just won the trials ‘Grand Slam’ – the SSDT, the Scott and the British Experts. Fraser found an unobtrusiv­e bike which was deceptivel­y quiet in operation and seemingly docile in action until the throttle was cracked open when the cams would rocket the bike up, say, a steep incline. Fraser took particular note of how easy the controls were with brakes, clutch and throttle featherlig­ht in operation and the suspension set to perfection and all-in-all pronounced the bike as ‘…probably the most successful of all time…’

The view from the south

AMC, based in London, was pretty much a local company for Kentish man Gordon Jackson and by 1961 he’d been in the works team for a good few years, he was actually coming to the end of his motorcycle trials career and soon to be trying car trials where he would attain equal star status. AMC also had a love/hate relationsh­ip with the press and often refused to advertise thanks to a mildly critical report in a magazine feature, or so legend has it. Thankfully by the time Gordon Jackson had won his third SSDT in 1961, by losing only one mark for the whole week, AMC were more predispose­d to journalist­s and The Motorcycle’s George Wilson was invited along to try what was to become the legendary 350 AJS. Still covered in the peatier bits of Scotland here was a bike that would easily be on the startline for another SSDT with little more than a rinse off, change of oil and the petrol tank topped up.

The bike was a little different from the production version so, unlike Miller who had no need to be seen on what was being

sold, Jackson’s bike had to pay at least lipservice to the production range. In reality the company used quite a few tricks to make the bike more to Gordon’s taste, the more radical ones were inside or hidden by paint. Less skuldugger­y was needed with components ordinary buyers could copy such as an alloy oil tank between the engine plates, alloy rims for the wheels and rubber tube fork gators.

Inside the engine were components from the 7R road racer also made by AJS though for the Scottish ex-wd cams had been fitted to tame the bike down a little but it was still a feisty bike. This would be in part thanks to the lower weight of the 350 compared to a standard bike and a big help in reaching the 265lb claimed weight must go to the Reynolds 531 tubing used for the frame and shortened sub-frame. Alloy engine plates and wheel rims also add lightness as does a tubular gear lever.

The engine is of course all alloy already but AMC used magnesium castings for various components such as the rocker box covers and gearbox castings. A lightweigh­t silencer on the end of a high-level exhaust pipe shaved a pound or two off. As with GOV 132 as many nuts, bolts and washers were made of lightweigh­t material as was practical and there was extensive use of the drill to create lightness. One neat trick was to do away with the steel oil tank and fabricate an alloy one which sat between the engine plates above the gearbox.

When Wilson fired the bike up, he was reminded of AJS’S skills of making machines mechanical­ly quiet and on the go the tremendous low-down torque of the motor too was noted in his report. What he wasn’t told at the time was AMC had reposition­ed the engine an inch back in the frame to alter the balance point of the bike. He was given or allowed to measure a few other dimensions though, such as footrests a couple of inches further back and only 19in from tip to tip while the prototype alloy petrol tank measured a mere 10in where the rider’s knees would be.

There is an interestin­g photo in the original feature with George Wilson in sports jacket and riding breeches, tie and cap perfectly straight as he tackles a nest of rocks observed by Jackson, AMC comp boss Hugh Viney and Ralph Venables as he accelerate­s over the slab in front of him. The razor-sharp handling, perfect suspension settings of AMC’S Teledrauli­c forks allied to the slimline Girling rear dampers keeping the journalist spot on line. Wilson ventured in his summing up of the model it had the renowned ‘plonk’ of Viney’s earlier works AJSS but allied to the zip needed for the changing face of trials riding. 

 ??  ??
 ??  ??
 ??  ?? Gordon Jackson on 187 BLF during that winning ride.
Gordon Jackson on 187 BLF during that winning ride.
 ??  ?? On the very last day Miller rode GOV 132 competitiv­ely, he won.
On the very last day Miller rode GOV 132 competitiv­ely, he won.
 ??  ?? Peter Fraser lines up GOV 132 to tackle some sections.
Peter Fraser lines up GOV 132 to tackle some sections.
 ??  ?? Freshly restored and ready for action...187 BLF.
Freshly restored and ready for action...187 BLF.
 ??  ?? Is this the most famous photo in all of trials riding? The Dab!
Is this the most famous photo in all of trials riding? The Dab!
 ??  ?? When you get there Peter... wind it on.
When you get there Peter... wind it on.
 ??  ?? It’s a big motor even if it is a short stroke.
It’s a big motor even if it is a short stroke.
 ??  ?? Wearing Gordon's number from 1961.
Wearing Gordon's number from 1961.
 ??  ?? View from the drive side shows lots of tucking in for bits.
View from the drive side shows lots of tucking in for bits.
 ??  ?? It is possible to read the speedo when it's in this position.
It is possible to read the speedo when it's in this position.
 ??  ?? Both bikes will be together at the show and undoubtedl­y Miller’s stand will be inundated with people wanting to get the real scoop, asking which bike is best. Though I dare say I know the answer Mr Miller would give…
Both bikes will be together at the show and undoubtedl­y Miller’s stand will be inundated with people wanting to get the real scoop, asking which bike is best. Though I dare say I know the answer Mr Miller would give…
 ??  ?? Come on Gordon, let’s re- create the dab...
Come on Gordon, let’s re- create the dab...
 ??  ?? AJS always had their magnetos at the front.
AJS always had their magnetos at the front.

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