A  History of Classic Racing  50cc Motorcycles


Duncan Mitchell, being a Scot, had the broadest of accents and when speaking you had to listen attentively to understand what he was talking about. He was a "character" who could have sold "Coals to Newcastle." His enthusiasm for 50cc racing was so intense that he was instrumental in talking the management of Brands Hatch Ltd. into holding 50cc races at the circuit in 1958. Also, with the interest in 50cc racing taking off, he was one of the founder members of the Racing 50 Club, and was secretary until early 1962. The R50C was a re-naming of the Chiltern 50 Motorcycle Club. In 1961 he was talking about producing a 50cc racer using his own designed cycle parts and using a Demm engine. He was then running a company called Moto-Decla out of Stevenage, Hertfordshire. More on this later. (Picture: Duncan Mitchell with Barbara Bound at a Chiltern 50 meeting. Barbara is on an Itom.)(Click for Barbara's Page)

The Heldun Engineering Company took its name from the founders, Helen and Duncan Mitchell and it commenced production in Dudleston, Shropshire before later moving to premises in Birmingham. Using proprietary power units sourced from Germany and Italy, the firm offered an extensive range of 50cc 'featherweight' models, both complete and in kit form.

The new Marque the "Heldun" was born in 1965. The Company was new to the 50cc motorcycle production market and had, like other manufacturers of small motorbikes, seen a gap in the market that they could fill with their type of  products.  They described themselves as the "Company to make the first British made 50cc road racer" but an argument exists as to whether Britax was there first. Heldun were at the time seeking export markets for their hand-built models and a few of the production racers went to the Scandinavian countries in 1965. These were Sachs two stroke engine based bikes. They also intended to make their machines available in Britain by the New Year of 1966.

For the UK market they decide to develop a different racing model to the ones sent to Scandinavia and moved away from the two stroke. Heldun then heralded the new racers birth and its first flight, it was the Heldun 50cc HAWK racer. The bike was a prototype machine and was to be ridden by a young 18 year old Rex Caunt who, by the way, currently runs Rex Caunt Racing and has developed many 'add-ons' of electronic ignition systems and BSA Bantam race parts. 

This Shropshire based firm, Heldun Engineering, put together a smart rolling chassis, as can be seen in the photograph and used a European double overhead camshaft engine to propel it. We have not been able to identify the manufacturer of the engine but Heldun were able to get 8bhp from it at 15,000 revs. It was a 6 speed unit and it was fitted with a Novel two speed primary system which gave it a 12 gear capability.  Sales of this bike did not get off the ground and for whatever reason the Company moved to the small village of Knighton (Powys). near Llangollen, Wales in 1965.

The race bikes, sent over to Denmark and Sweden, competed in a number of races and held their own until the Kreidler and other more advanced machines came into private hands. 

1965 Anders Bengtsson with his Heldon

 Oluf Steffensen on a Sachs Special next to the Heldun 1965

The start of the race. The Heldun No 61 Anders Bengtsson is on the back row. No. 39 is Bjorn Carlsson on a 3 speed JLO based G50, also No.34 is Lasse Johansson 

Cees van Dongen and Oswald Dittrich on their Kreidlers came 1st and 2nd in the race

The Heldun No 61 with Anders Bengtsson came in 10th in the event at Ring Djursland Denmark in 1965

At this time, 1965, the market was asked to stand by for new models from Heldun. The Company brought out four new designs. A Racer, Sports/ Racer, a Trial bike, a Trials and a Scrambler. Engine units were a variety of German and Italian products, both two and four-stroke, but fitted with Amal carburettors and considerably modified by the makers. On the overhead-valve engines, for instance, the inlet ports were opened out and cam followers were reground to a flat-base pattern, resulting in a considerable power boost. Modified porting and expansion type exhaust systems gave a similar lift to the two-strokes.

As promised to the market, these designs were developed into the 1965 range, which was comprised of two two-stroke racers, the Hawk and a Sports Moped/Racer the Hurricane, respectively with five and four speed gearboxes, The Harlequin Trail. the Husky ohv trials mount and a Hammer two stroke scrambles mount, in other words a quartet of Harlequin roadsters; the Harlequin Sports pair  were two-stroke powered, while the Harlequin' Supremes made use of an ohv engine with a three speed box.

A further distinction of the Harlequin models was that the deluxe versions, where appropriate, were equipped with a dolphin fairing, battery and rectifier lighting and 60 mph speedometer.

Perhaps the most unusual of the Heldon models was the Husky trials, which employed a pivoted front fork that Duncan Mitchell had tried out in 1963 when he developed a 50cc four cylinder racing motorcycle: (need another page to cover this), all other models had a telescopic fork system. The machine could be supplied with either a twist grip or foot controlled gear change. For trials use, the overall gear ratios were 49.01, 35.94 and 22.87 to 1, but an alternative rear wheel sprocket was available to raise these to 36.26,.26.59 and 16.92.

Glass-fibre fuel tanks, were used throughout, with quick-action filler caps on racing models and the same material forms the seat base and mudguards of the Husky. Fibreglass tanks of the style used by Heldun were available in Italy and were used on other 50cc Motorcycles. This was seen as a reasonable way for Heldun to go.

Tyre sizes for the Harlequin roadsters were 2.25 x 17in. The Heldun Hawk and Hurricane have light-alloy rims shod with Dunlop 2.50 x l8in racing covers while the trials machine uses a 3.00 x 17in front and 3.50 x 17in rear Trials Pattern Universal. 

A brief test run on the prototype Husky indicated that it certainly had a surprising helping of punch. However some criticism could have been made of the high-level exhaust system, but the makers had said that a redesign was in hand and, on  production versions, the rider's left leg would be clear of the exhaust pipe.

The home-market sales were to be handled by the Birmingham Fibreglass Moulding Co, 118, Leopold Street, Birmingham, 12. The two de luxe Harlequins would be marketed as complete machines (as also would be the Hawk and Hurricane racers) while the 'Husky and the standard Harlequin roadsters would be offered in kit form. As a motorcycle Kit was classed as parts rather that a complete bike it was not subject to Purchase Tax,

At a later date Heldun hope to manufacture their own units; work was proceeding on a prototype two-stroke twin and an overhead-camshaft single. Also on the stocks was a double front-brake unit which employed a British hub with shoes and brake plates of their own design which would have been fitted to the sports moped and production racer.

The Heldun Range

Production Racing Model /   Ex-works Colours Purple, Red and Hammer Silver
49 c.c. Two-Stroke Power Unit.
5-Speed Close Ratio Gearbox.
12-volt Coil Ignition. Contact Breaker.
Tuned Induction and Exhaust Systems.
Duplex Frame. Teledraulic Forks.
Swing Arm Rear Suspension. 
Racing Tank and Saddle. Fibreglass 
Dolphin Fairing and Double-Curve Racing Screen. 
Ball-Ended Controls and Footrests. Alloy Rims and Full-width Alloy Brake Hubs. 
Racing Tyres: 2.50 18.
Speed: 80 mph plus! Weight: 140 lbs.

Heldun Hurricane/ Harlequin
Sports Roadster/ Trail Model/ Colour British Racing Green and Plain Silver 
49c.c. Two-Cycle Power Unit.
5-Speed Gearbox. Magneto Ignition.
Fully-Silenced Exhaust System.
Duplex Frame. Telescopic Forks.
S.A. Rear Suspension. 
Sports Tank and Raised Back Racing Saddle.
Stainless, Steel Mudguards. 
Lightweight Sports Fairing. 
Ball-Ended Control Levers. 
5-in. Headlamp, Rear lamp, Electric Horn. 
Centre-Stand. Chrome-Plated Tyre Inflator.
Tool-box and Toolkit. 
Chrome Steel Rims and Full-width Alloy Hubs. Tyres: 2.25" 17".
Speed: 65 mph. Weight: 120 lbs.
(Racing Conversion Kit available)

Trials Model/   Colour Flame with Hammer Silver
49 c.c. Two-Stroke Power Unit.
5-Speed Gearbox. Magneto Ignition.
High-Level Exhaust System.
Duplex Frame. Leading-Link Front Forks or Telescopic. 
S.A. Rear Suspension. 
Slim Tank and Trials Saddle. 
Stainless Steel Mudguards, Crankcase Guard. 
Ball Ended Controls and Footrests. 
Chrome Steel Rims and Full-width Alloy Brake Hubs.
Tyres: Front, 3.00 17 Trials Universal, 
Rear, 3.25 16 Trails Universal, 
Speed: 55 mph. Weight: 140 lbs.
(Lighting Kit available as an extra)

The Heldun HAMMER
Scrambler Model
49 cc. Two-Stroke Power Unit.
5-Speed Gearbox. Magneto Ignition. 
High-Level Exhaust System.
Duplex Frame. Leading-Link Front Forks Oil-Damped. 
Swing Arm Rear Suspension. 
Sports Tank and Moto-cross Saddle. 
Stainless Steel Mudguards, Crankcase Guard. Ball-Ended Controls and Footrests.
Chrome Steel Rims and Full Width Alloy Brake Hubs.
Tyres: Front, 2.75 . 18 Sports.
Rear, 3.00 17 Sports.
Speed:[ 65 mph. Weight: 135 lbs.

                               Model                                                              £ s d

49 cc      Hawk 5 speed racer (No P Tax)                         £225 0 0
49 cc      Hurricane 4 speed racer (No P Tax)               £170 0 0
49 cc      Hammer 5 speed Scrambles (kit)                    £142 0 0
49 cc      Husky 5 speed Trials (kit)                                  £138 0 0

                         Model                                                                       £ s d

49 cc      Harlequin Sports  (kit)                                              £114 0 0
49 cc      Harlequin Sports de Luxe                                        £150 3 9
49 cc      Harlequin Supreme ohv (kit)                                 £129 12 0
49 cc      Harlequin Supreme de Luxe ohv                          £167 15 8

1965 Heldun 50cc Harlequin Sports Special

Frame no. HD HNS 002

Harlequin '002' was restored by the late Glyn Davies of Tenterden, Kent, who was pictured with it in Classic Bike magazine (May 2008 edition). Glyn's notes on file reveal that the machine had been in a good state of preservation when acquired, apart from the damaged glass-fibre fuel tank, which he replaced with a Yamaha TY80 Trials tank

The bike had gone through various stages of change during its life and modifications to the brakes, footrests and engine were evident. The engine is now of JLO manufacture, widely available on the continent at that time. 

The ILO-Motorenwerke GMBH (also known as JLO) 2-stroke motor company in Pinneberg, Germany existed from 1911 to 1990 and was one of the biggest manufacturers of two-stroke engines in Germany. The term ‘ILO’ comes from the artificial language Esperanto and means "tool". 1n 1959 it was sold to Rockwell Manufacturing Company.


Part way through 1968 Heldun ceased trading, but before then its products had competed in the Isle of Man 50cc TT and one even finished the Scottish Six Days Trial, earning its rider John Buchan a bronze medal.


This was not before the works Heldun Hawk had competed in the short-lived 50cc T.T. in 1967 in the hands of the lightweight rider P J Walsh, more used to MV and Aermacchi, who did not finish. The same fate befell Heldun rider Doug Cash in 1968. This machine, from its frame number is thought to be one of the TT entries,  went on to further use in UK short-circuit racing in the hands of A F Clapham and was then retired. Picture: (1969 - Arthur Mills riding a 50cc Minarelli is followed by A F Clapham on the Heldun Hawk . This HAWK is the machine that competed in the 1968 50cc TT.)

Nick Mayo Heldon Hawk 1968 50cc TT Position 9th

1967 50cc TT Results

Robin Stopford Heldon Hawk 1968 TT Position 8th

1968 50cc TT Results

The Helduns were also present at the Isle of Man Ultra-Lightweight 50cc TT where Robin Stopford finished eighth R P Stopford Heldun - Time:  Speed: 58.18mph  and Nick Mayo ninth, Heldun - Time:  Speed: 56.97.   P. J. Walsh was also entered but unfortunately was a DNF on his Hawk.  Pictures courtesy of FoTTofinders Bikesport Archives



Additions to the History Site

Received: 01-02-2019

A post to the History page from a group member Richard Ross.

I came across on your website the excellent piece on the Heldun 50cc machines. Your article is the most comprehensive account of this short-lived company I've found. I've a particular interest in the Heldun operation. As young lad of about 14 I happened on the bikes and the very hospitable pair who were behind this small-scale operation. This was at the time when the enterprise had a ‘show room’ in the boarder town of Knighton (Powys).

I happened to be on holiday and wondering through the town I spotted the Helduns in an empty shop. What caught my eye, as an enthusiastic youth, was the tiny four cylinder machine in the back of the shop. I recall going into the shop and asking the two kind people sitting there what capacity this minute four cylinder bike was. I was suitably astonished when they told me it was 50cc.

I have wondered if this is the same 50cc four that is shown in the Sammy Miller museum. I suspect it may be – but I believe the description of that machine in the museum contains no reference to the Heldun connection. At that time, 1964/5, the road bikes were being fitted with Italian Demm four-stroke engines. I remember that the ‘trials’ version was fitted with clip-ons turned up-side down, an arrangement that struck me even then as not an ideal configuration!

I was invited to the workshop, also in Knighton, where the bikes were in the process of being constructed. The Mitchell's were very kind and welcoming.

Editors comment to Richard: The reference to the 4-cylinder racer, "at the back of the shop", it is the same engine as the one at the Sammy Miller museum. It was never constructed under the Heldun name as Duncan acquired the prototype engine from the Designers/ Creators and then developed it as a test bed machine, initially for his own racing interest. It never raced in anger. Duncan created the engine at the museum using some of his own castings from this one. Those responsible for the prototype engine were Maurice Raby, his 50 c.c. Mini Motor-powered "Fitz-Ray Special" was seen at Blandford as long ago as 1955 and F. Eric Fitz-Hugh, ideas man, practical engineer and the "Fitz" half of the partnership. Please click here to read the story. 


This marketing pamphlet was sent by, Dave Beare, of the The National Autocycle & Cyclemotor Club Ltd. He commented: "I attach the two scans of a Heldun leaflet (unfortunately not dated) but does cover the 1967/68 range, that I've featured in the February issue of the NACC club magazine "Buzzing".

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