Cyclemotors were popular during the 1950's, right through to the early 60's for the most successful brands. They were usually clip-on two stroke motors used to power assist a bicycle. Although there were many manufacturers, the most popular were the Trojan minimotor, the Powerpak, the B.S.A. Winged Wheel and the Cyclemaster. The latter two were not simple clip ons but were complete powered rear wheels with some cycle manufacturers purposely supplying bicycles without the rear wheel.

These engines were also popular for assisting tandems! A story in the Magic Wheel of 1955 tells how an intrepid young couple toured Scotland on a Cyclemaster/Tandem. They covered 749 miles using 4.5 gallons at a cost of just over twenty shillings (£1) and carrying 24 stone in weight!

Click on the picture to see a bigger view.

Simple construction meant that you could motor to work, strip and decarbonise the engine during your lunch break ready to motor back home again at end of the working day.

Eventually these little units were ousted by the more powerful and stylish mopeds and scooters that became fashionable from the early 60's onwards, although there is still a similar American unit available.

So my first experience of these is the Cyclemaster that I have recently bought from Cyclemaster expert David Butler. 

My unit was first registered in 1957, as 429 CMU, and is the 32cc version, early models were just 25cc. Its a two stroke but has a rotary induction valve. Its the first time that I have heard of this but I am told that this type of engine is more efficient than a standard two stroke. The pictures show the original state of the engine and bike, unused since 1967. Its not painted brown, that's the rust! Nevertheless, David has done a marvellous job of refinishing and reconditiong the unit (that's the finished article shown at the top of the page) the bike has donated many parts and I have kept the frame.

The wheel itself is heavy duty 26" x 2" Westwood rim with the motor built into it. The crankshaft drives through a clutch and a system of chains and sprockets. As yet I am unable to try it since the frame is stripped and being refinished but I am confident that David has done a thorough job; his bill for new parts alone came to £111. 

Update October 2002 (only two years on!)
The frame has been stripped and repainted but I still haven't fitted the engine. The reason is fairly simple, really. The frame is a Lady's model and I have to admit, rather stupidly, that I would feel silly riding a lady's bike. 

So the next plan was to fit it to my Triumph roadster bike. Unfortunately the rear stays would have to be splayed slightly to accommodate the unit and I would probably have to file the drop-outs to take the axle. I really don't want to spoil this bike so it is on to plan three........ Actually this one was sold some time ago!

Next weekend, October 13th, 2002, I'm off to buy another Cyclemaster, this time already fitted to a Gent's roadster! It also makes the idea of owning two Cyclemasters more plausible when I explain to my wife why I need it! You can see the second Cyclemaster here.

Not only that but I'm going to see a Trojan Minimotor, for potential purchase, on the same weekend. This is the one that I have always wanted. Its much simpler than a Cyclemaster, though probably less refined since it doesn't have a clutch or a lighting coil. The advantage, to my mind, is that the Trojan simply roller drives the standard rear bicycle wheel. Amongst other things, you can still pedal if you run out of petrol or the engine expires and repairing a puncture is little more complicated than a normal bicycle puncture. The page on the Trojan Minimotor can be found by clicking here.