Click on the photo to see a larger version. This poster shows some of the various positions that early motorbike designers chose to place the motor in the chassis. A few oddballs to be sure: The Raleigh was front wheel drive, while the Enfield shared the same motor position but drove the rear wheel with a long drive belt. Not to be outdone, Singer put the motor inside the rear wheel
Werner Bros famously placed the motor just in front of the pedal cranks, an advantageous position to keep the weight low and provide enough room for the various mechanical systems as well as the rider’s legs. But several other designs put the motor in almost the same position, such as the F.N., Weller, Crypto, Quadrant, Royal Enfield, Morris, Davison, Princeps, etc.
B.A.T. is notable as one of the more modern designs. The eliminated the pedals and put the motor squarely where it ended up with the other designs ten years later. B.A.T bikes were pretty advanced in the veteran era, with a patented sprung frame. Not sprung wheels, but a sprung subframe that mounted the rider’s seat and footpegs, thus isolating the pilot from some of the harshness of the road. The wheels still danced about…
Nov. 16 1902 Motorcycling magazine
While the following photo looks strange, it is actually very much like the three wheeler De Dion Buton’s of the turn of the century, but with only two wheels. The motors had a pinion gear on the crank shaft, mated to a ring gear on the rear axle of the bike. Ariel famously moved the motor to be ahead of the rear axle, improving the weight distribution on their trikes. Image from The Motor, Dec 13th 1904.