The Mini Motor was one of the best-known of the British clip-on engines, and was introduced in Great Britain in 1949.
Though rarely referred to as such, the Instruction Book for the Mk 5 model (the last of them) describes it as a ‘Gearless Cycle Outboard.’
1957 Trojan Mini-motor ‘Gearless Cycle Outboard’
on Gents Raleigh Superbe.
This restored Mini-Motor Engine is in excellent condition, while the Raleigh ‘Superbe’ bicycle has wonderful original unrestored paintwork.
This is one of the nicest outfits I’ve come across. I bought it in 2007 for my personal collection, and it has recently come out of storage. My mechanic has serviced, cleaned and polished it.
It’s a practical machine for regular cyclemotoring, as well as to display at shows and rallies. You can see a video of the engine running further down the page.
The Mini Motor was one of the best-known of the British clip-on engines, and was introduced in Great Britain in 1949. Though rarely referred to as such, the Instruction Book for the Mk 5 model (the last of them) describes it as a ‘Gearless Cycle Outboard.’
The Trojan Minimotor was originally designed by Vincent Piatti in 1946 as a unit to power portable lathes; he saw its advantages as a cycle-attachment and introduced it in Italy as the ‘Mini Motore.’
Five models were produced in Britain at Trojan’s Croydon factory, from the Mark I in 1949 to the Mark V in 1955. The improvement for 1951 was a decompressor added to the cylinder head to aid both starting and stopping.
The engine sat above the bicycle rear wheel, which it drove with a friction-roller on the left-hand end of the crankshaft. On the right, there was a Wipac flywheel magneto, and between this and the roller, a crankcase with bobweight flywheel and a horizontal iron barrel. An alloy head closed this, and the capacity was 49.9 cc for the conventional two stroke unit. The petrol tank went over the engine with the number plate fitted behind it. A means of lifting the roller clear of the tyre was provided .
The unit could drive a bicycle at 30 mph, which was probably as fast as you’d want to go on a normal cycle under normal road conditions. In a postwar Britain with a shortage of new vehicles, motorists found them ideal for short trips, commuting to the station or the office, or to the shops to fill up the front basket. Some were even fitted to tandems, where they proved equal to the task of hauling two people along at 20mph.
Text from the Cyclemaster Museum – http://cyclemaster.wordpress.com/page-13-the-minimotor/
FRAME & ENGINE & S-A HUB NUMBERS