Innholdsfortegnelse for Issue 44 Autumn 2017 i Classic Dirt Bike

The weight game It is the task of feature writers to attempt an explanation of complex physics and automotive dynamics in as few words as possible. While weight reduction is a desirable aim for a competition bike designer there are different types of weight, these being ‘all-up’ ‘sprung’ and ‘unsprung.’ Attention to each area can alter the way a bike feels and it’s easy to get it wrong and alter the balance of a bike. Briefly – and this subject is an involved one – a lower overall weight is generally good but carving lbs or kgs off one end of the bike and not the other will lower the weight but alter the balance point… then there’s sprung weight which is the bulk of the bike above the suspension.…

There’s a bit of personal involvement in this event as the Castleside Trials Club is ‘my’ club... and if I’d not ridden this one there would have been raised eyebrows from the committee. The Kia series is a popular one for people of my age group and tends to feature the bikes we rode in the Seventies in sections which reflect that time. I suppose it’s rather like the pre65 trials scene was for those who rode in the Fifties and Sixties. So, traditional Seventies trials bikes on a course I for one have been riding on since those days. Unlike the smaller courses forced on organisers by the spread of the urban sprawl and the motorway infrastructure, this particular course at Lambshield near Edmundbyers has survived and is pretty…

PART ONE The schoolboy movement of the late Sixties revolutionised the sport of motocross and a few years down the line would produce world champions in Graham Noyce, Neil Hudson and Dave Thorpe. But long before these superstars materialised, tearaway teenagers had been making their mark in the sport, much to the annoyance of the established stars of the day. One such youngster was future double world champion, Jeff Smith. Having made his mark as a trials rider and captured the first of two ACU Stars in 1953 at the age of 18, the precocious teen turned to scrambling, winning the Dutch GP in 1954 and taking both the supporting races at the British GP the same year; his father wouldn’t let him race in the GP as he thought…

Those of us who were youngsters in the early Seventies and reading the motorcycle press of the day had absorbed everything about the ISDT, the long distance trials where Triumph had exceeded all expectations and produced winners. We had focussed on such motorcycles as the TR5, the Trophy 500, we knew all about the wartime legend of the square barrel over the later round barrel, how could we not, it was written down in front of us. We knew the ISDT was the ultimate test of motorcycle and rider and that the competition departments of not only Meriden were focussed on success in this demanding theatre of skill and determination. We knew the motorcycles needed for this ultimate test would be superb in every respect… if only they would produce…

The way of the magazine world is fascinating in many respects, especially where an archive is involved. Here at Mortons the archive is probably the company’s most valuable resource and also its most enticing department. You see, going in to search for pictures involves looking through boxes of images and magazines too. That’s when things innocently change the course of a search. Take this Velocette-based scrambler for instance – there I was, looking through boxes for, of all things, a Panther sidecar outfit when the photo of the young lad checking his rear brake fell from the folder. Clearly working on a scrambler and a pretty neat looking one too, interest was piqued. The information on the rear of the image showed it entered the MotorCycle editorial offices in September…

For an engine designed in the 1930s to still be the choice of a racer determined to win in the then ‘modern’ era of 1968, the basic concept of that engine must have been pretty good. At that time, The Motor Cycle’s man VicWilloughby visited multi-time British grass track champion and talented engineer Don Godden to find out what the lad did to make those engines work way beyond the maker’s wildest expectations. Immediately he found there were remarkably few changes from its inception to the latest 1960s model. The crankcases were cast in the magnesium alloy known by its trade name of Elektron, the con rod was either in Duralumin – another trade name – or steel. Willoughby went as far as to say the drawing used in the…

When looking to make any improvements, you will need a few bits. As standard, the military Rotax engine Can-Am has a fairly simple method of actuating the clutch. Inside the case there is a ramp cast and this has three piddling little ball bearings in it. A pressed steel fabrication rides up on the bearings as the lever is pulled. It works well enough on the road and even on a trail ride, but in the cut and thrust of an enduro, things get a little tougher. Last year’s Hot Trod Vinduro was the final straw for my clutch hand, as I realised by the end of the Sunday all I was managing to do was take up the slack in the cable rather than lift the clutch. The Can-Am…

Sometimes an event is so simple it takes your breath away… take Red Marley Hill Climb for instance. There’s a start line, then 400 yards or so away there’s a finish line. Four riders line up at a time, the gate drops and the first two over the finish line go through to the next round. As that cute – other points of view are available – furry creature on UK telly ads is fond of saying “simples!” And it really is that simple to do. The bit which makes it difficult is it’s up a hill which gets progressively steeper nearer the end... and then gets really steep very quickly at the end... oh, and there are three other riders, none of whom will back off, aiming for the…

The winner of Star Letter will receive a prize from the Bel Ray catalogue Write to us at: ClassicDIRTbike, PO Box 99, Horncastle, Lincolnshire LN9 6LZ. CDBeditor@mortons.co.uk Sandiford’s ISDT Cheney I enjoyed the piece on Jim Sandiford’s Cheney, but a couple of things stood out as odd. The bike has been rebuilt as per 1971 – Isle of Man – spec, so why has it got the 1970 (when the ISDT was in Spain) – number on it? There were a number of changes, the most visible being the change of the original red anodised tanks and the front forks. Neither of those parts were really up to the job. I cannot be absolutely sure but I think the pre-event trip to the Welsh Two-Day was canned for some reason…

Lincolnshire’s Cadwell Park race circuit is no stranger to close racing, though generally it is on the tarmac circuit. However, there have been a number of top line motocross races held there too. Though our image is of Dot rider Pat Lamper and Greeves man Alan Clough, both of whom put up a decent performance on the 1.1 mile circuit marked out on the infield area, it was to be 20-year-old Belgian Joel Robert’s day as he made his impact on the motocross world. In a meeting-long tussle with UK’s Dave Bickers, which saw Bickers win the first leg and Robert the second, it was the Belgian who would leave Cadwell on top of the world.…

The aim to produce the lightest possible competition bike has always been high in the priorities of any trials rider, balanced of course with the need to make the bike strong. Top line riders such as Sammy Miller, Gordon Jackson, Johnny Brittain and Don Smith, to name but four stars, recognised this and often were at odds with their team bosses over modifications to machines. Miller for instance, is on record as saying he occasionally had to park his Ariel out of sight in case he was forced to undo his handiwork by the factory. Gordon Jackson too would occasionally have to hand back light bits in order to be seen to be competing on what was being sold. So too did Johnny Brittain, whose Royal Enfield at one time…

As history will record, American Suzuki rider Brad Lackey would finish the season as world champion. However, at this stage in our story that was still to come and the motorcycling press here in the UK was full of how well the British riders could do at their home GP. In a full page preview of the Farleigh Castle contest, MotorCycle Weekly reckoned things looked good for a home winner. With British stars such as former 500cc world champion Graham Noyce, reigning 250cc world champion Neil Hudson and rising star Dave Thorpe all consistently being in the top five at the previous nine GPs, you can see why the press felt this way. In interviews with the three Brits, all of them felt that at this stage in the season…

Due to one thing and another cropping up at various times, my own collection of dirt bikes has been neglected a little recently. Like most enthusiasts I’ve a few bikes in the shed and they’re there for reasons which will be familiar to a lot of readers. Longest standing member of what has been referred to as ‘my fleet’ is the 250 Bultaco Sherpa T I’ve had from new and it was the subject of a rebuild series itself 20 or more issues back. The newest machine – as in new to me not ‘new’ new – is a TY250 Mono Yamaha, similar to the one I had in the Eighties and in between there are a scattering of British and European machines with one thing in common… they all…

Word going round the paddock at the Scottish Grand National MX was along the lines of “what a fantastic setting…” and it certainly was a great place to hold a scramble. Laid out by the Scottish Classic Racing Motorcycle Club’s scrambles section, the track was not particularly technical but provided lots of close racing with few spills and a great weekend for competitors and spectators alike. CDB only managed one day – Sunday – which was fine, warm and sunny, though apparently Saturday had some interesting weather. In any case, the track was in prime condition thanks to the rain, with more than one rider saying how dusty it would have been otherwise. Riders from several European countries such as Belgium, France and Eire, plus a few coming further afield…

Acasual comment led to a large part of the 1970s and 1980s Bultaco works trials team assembling near Kendal for the Westmorland Club’s special trial, to celebrate not only the marque but to raise funds for Cancer Care. Trials fans from the Seventies won’t need to be reminded that Martin – youngest of the three Lampkin brothers – was the first official world trials champion in 1975, nor will they need reminding the legend was lost to the world when he succumbed to cancer last year. Westmorland Motor Club assembled a number of notables from Bultaco – flying them in from Spain, France, Yorkshire and Lancashire to celebrate in the summer sunshine. Such stars included Oriol Bulto who had the task of marshalling his young charges on various works teams…