The Cairns Mocyc
Neil Cairns relates how he oh so nearly inherited a motorcycling empire!
When my father Frank married his first wife in 1935, he fell out with his younger brother, Jim. The reason for the split was the two brothers’ wives hated each other and so things became impossible. The family argument also split up the company which the brothers were running together and that built electrical equipment in Todmorden in Lancashire.
My father left, joining the Air Ministry and eventually was put in charge of building airfields; 1939 arrived very soon after that. His younger brother Jim also ran a motorcycle and bicycle shop in Blackburn Road, Accrington, so once my father had gone, the family business also began to build bicycles to sell in the shop. I can remember that shop in Accrington with a big sign out the front with ‘CAIRNS FOR RUDGE’ on it, but only because it was our one and only visit as we were going to my grandfather’s funeral. Consequently, we knew very little of what occurred after 1935; my father married my mother after the Second World War after his first wife had died in childbirth, which was then all too common). Nearly a motorcycle empire…
The years rolled by and, though my siblings and I were all sent birthday and Christmas presents, no other contact was made with my uncle and his family. So it was with real surprise that, in my middle sixties and now retired, I found out I might have in my youth nearly inherited a motorcycling empire. Note, I did say nearly… Read on.
The first shock was I found out that after the war the above shop only stocked bicycles and mopeds, nothing bigger than 50cc. But it was the mopeds that were the surprise; they were ‘Cairns Mocyc’ with a GYS 49cc two-stroke engine clamped to the front handlebars and forks. By the time we visited in the late 1950s for Jim’s funeral, only bicycles were being sold.
But back to 1935. Jim had taken over the family firm now on his own. It built very staid and standard safety cycles with rod brakes, even in 1935 these machines looked decidedly oldfashioned. But they were well made, solid, dependable and very long lasting. An export market to South Africa subsequently developed and these sales kept the firm solvent. The Second World War came and went, as did military service. The company now had its factory in Stoneswood Mill in Todmorden, Lancashire.
Enter the GYS engine
Meanwhile, down in Bournemouth, Hampshire, the GYS Engineering Company had developed a little 49cc clip-on two-stroke moped engine. It now needed an outlet for its product and the rationing of petrol that lasted almost up until the 1950s was an incentive for people to buy cheap, easy-to-run mopeds. GYS claimed it was the ‘first all-British unit on the market’, and the engine drove the front wheel using a carborundum roller bearing on the front tyre. The engine was bolted to the handlebars and the front wheel’s axle, strengthening the front forks (as it was for use on your average pedal cycle). The unit could be lifted off the tyre for ‘neutral’ and moved back on to it again to ‘drive’ using a lever. A small spring damper assisted the contact of the carborundum wheel with the tyre. A handlebar-mounted lever operated the throttle when moved forward, or the decompressor when moved rearwards. A decompressor was required to be able to start the engine by pedalling the bike, closing it once on the move and the unit spinning over ready to fire up. It was basically a copy of millions of similar French machines, particularly the very numerous VeloSolex and the Birminghambuilt Cymota (which was a direct copy of a VeloSolex).
Jim was approached by GYS and in 1950 a contract to fit the engine to his bikes brought in much-needed work at the Stoneswood Mill. Alas, Jim was more of an engineer than a businessman, and within five years the clever GYS people had ousted him from his own board and taken over the company. Very angry over the behindthe-scenes plotting and backstabbing, he then concentrated on his shop in Accrington.
But all was not well for the GYS chaps, as while the moped did have good points, it also had some very bad ones. While the crankshaft ran on ball bearings with one end being the drive for the roller and the other the location for the WicoPacy magneto, the big end was a simple plain bronze bush.
To get sufficient lubrication to the plain bush the petrol-oil mixture ratio was 16 to 1. This was a lot of oil in the petrol – the more usual ratio then was 25 to 1. Also, the crankcase sealing was done with a thin felt washer on each side, held in by a steel washer. Any twostroke enthusiast will tell you that crankcase sealing on such a unit is vital, as the crankcase’s varying volume is used as part of the induction process. If the sealing is poor, the mixture gets blown out sideways and not up via the inlet port into the combustion chamber. But when new, this problem was yet to raise its head. And there was a very good reason the majority of other moped builders put their engines low down in the frame, or even behind the rider.
The little 49cc bore and stroke of 40mm by 40mm produced about 0.7bhp. It was fitted in the factory to the Cairns cycles and sold as the Cairns Mocyc.
Fuel was kept in a tank above the engine giving a gravity feed to the minute Amal 308. Down the offside of the engine’s frame was a cast aluminium silencer that could be dismantled in situ for the regularly required de-coke.
Two-strokes in those days would fill their silencers with unburnt fuel and oil as carbon, very quickly blocking the exit and ruining the performance.
A 16 to 1 fuel/oil ratio did nothing to alleviate this. Driving the front wheel gave good traction and the forward position good engine cooling – but alas, the faults outweighed these advantages.
As the engine was high up in front of the rider, it was inevitable that they got a good coating of oil from the exhaust all over them, the slowly wearing crankcase seal leakage adding to this. Eventually the leakage would become so bad the unit would be difficult to start and would stall at idle. This is probably one reason they usually ended up under a blanket in the shed.
The other reason is a bit more serious.
Oil starvation caused locking up
Using a plain bush in the big end and a high oil-to-petrol ratio, high continuous rpm could lead to lack of oil getting to that bearing. Add to that the fact that some owners were not reading the instructions and only using a 25:1 ratio (giving less oil for lubrication), this would most certainly lead to oil starvation.
That would cause a sudden seizure of the bearing and/or the piston, causing the front wheel to lock up. Few riders like to be catapulted over their handlebars at 25mph and rumour has it that the odd one not wearing a helmet was killed, there being no law back then enforcing the wearing of such items.
Such a bad name did the poor moped get that some stockists took them out of their showrooms to be forgotten in the back of their stores. Very soon the Stoneswood factory closed and, unknown to me, any hope of my ever inheriting a huge motorcycle empire had evaporated.
The death of the Mocyc
Some GYS engines were sold separately for owners to fit to their own bikes. A Jack Fletcher of Ashton Road, Denton, Manchester, advertised them as: “Fits any cycle; 225mpg; 30mph; £22.10s (£22.50) with 2/6d carriage (12.5p); HP Terms available £5 deposit”. That claim of the supposed mpg might attract a visit from trading standards today.
The GYS engine was also fitted by another firm, Colbi Autos of Walworth in London. But they fitted it behind the rider under the saddle. Here it was far less liable to soak the rider in oil and exhaust fumes or pitch them forward over the handlebars, but the unit was still prone to the crank seizing up on long runs at high rpm. Quite a few ‘stink wheel’ enthusiasts (two-stroke clip-on/moped fans) own unused Cairns Mocyc cycles fitted with the GYS motor, as well as unsold complete engine clip-on kits, all because the retailers lost confidence in the product and stored them away, eventually forgetting they were there and only to be found in the 21st century when the business finally closed or failed. A big thank you must go to David Hamner of the NACC and Hoppy Hopkins of the VMCC for help in researching this family history.