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Engine position and external transmission

A variety of different engine positions have been used in the past. For instance, some mopeds (e.g. the French Velo Solex) had the engine mounted above the front wheel, allowing the moped to also be used as an ordinary push-bike. A disadvantage of this engine position was that it made handling difficult. An often repeated remark is that “Riding a Velo Solex is like riding a bicycle with a sack of potatoes on the handlebars”.

Other notable models with this engine position are VeloVap and Berini M13, which also had roller-transmission. Last, but not least, there was the German-made Rex FM40, which had belt-drive transmission between the engine and front wheel.

Velo Solex - The self-powered bicycle



Rex FM 40 (picture found on Ebay)

Another possibility explored was placing the engine above the rear wheel, and raising the luggage carrier to a suitable height.

In Danish every-day parlance, a vehicle of this type came to be known as a ’røvskubber’ (= bum pusher), or merely a ’skubber’ (= pusher).

Most notable among this type of model were mopeds manufactured by Danish Diesella and BFC. Other less known Danish manufacturers are Jowa, Tiki, Bema, Jet and Star. With most of these ’skubbere’, the rear wheel was driven by the engine via a steel roller. The Star, however, had both a clutch and chain-transmission. Having the engine placed above one of the wheels gave these mopeds a very high center of gravity. This can be a nuisance when parking the moped, for instance, unless of course you have a very large footrest, but these are usually also very impractical.


BFC Trollet


Note how the Diesella and BFC engines are inverted



Yet another possibility was to place the engine on one side of the rear wheel. Though it did result in uneven weight distribution, this was a fairly good engine position. The best-known models of this type in Denmark are Victoria FM38 and ABG-Vap4, both of which have chain-drive to an extra sprocket on the rear wheel. In Germany, a similar construction called MAW was exceedingly popular.

Victoria "Vicky" FM38 (Picture found on German Ebay)

ABG Vap4

Why tread the pedals yourself?

These two pictures of CycleMasters were found on the Internet

-The magic wheel that wings your heel-

Mounting the engine on the frame was a fairly time-consuming job, and this was a factor which was exploited in the advertising campaigns for the motor wheel. All you had to do was to replace the rear wheel on your bicycle with a motor-wheel, mount the throttle and clutch on the handlebars, pour petrol in the tank – and off you went.

The most popular of the motor wheels were CycleMaster and Sachs. Some years ago, German Sachs put motor-wheels in production again and continued production for a considerable length of time. These bore the same name as the older models, namely ‘Saxonette’.

The crank-mounted engine was tested with various combinations of roller-, belt- and chain-drive. One model even had shaft-drive, This position gave a good weight distribution and a low center of gravity. As we know from later models, this was to become the preferred engine position.

Wooler 160 with roller-transmission directly to the real wheel.

Wet tyres caused problems with roller-transmission, as the reduced friction caused skids between the roller and tyre.

Here the makers explain how the tyres have more time to shed water before they reach the roller with roller-drive from a crank-mounted engine than with ‘skubber’ (= pusher) models.

Left: the BFC "Folkestafetten" with belt-drive to an intermediary wheel, and chain-drive to the rear wheel.

Left: Skylon 55 with roller-transmission to an intermediary wheel, and from this chain-drive to the rear wheel.