ner-a-car Technical Data

English Model A's and early US models have the same dimensions.
Bore 2.5". Stroke 2.75". Capacity 13.5 cu.in. = 221cc.
Compression ratio (simple) 3.8:1 (actual) 2.88:1
Early US models have just one brake, a left-foot operated drum brake in the rear wheel. The English Model A has the same drum brake, plus a contracting-band brake on the countershaft operated by a lever on the right handlebar.

English Model B's
Bore 70mm. Stroke 74mm. Capacity 285cc.
Compression ratio (simple) 5:1 (actual) 4.05:1
These are identified by the removable cover on the transfer port on the right hand side of the cylinder, with an entwined "S S" on it.
There are two drum brakes, both on the rear wheel. The left one is foot-operated, the right one by a lever on the right handlebar.

US models from late 1924
Bore 2.625". Stroke 2.875". Capacity 15.5 cu.in. = 255cc.
These can be easily identified as they have vertical fins on the top of the cylinder. (Earlier ones have horizontal fins.) They also usually have an engine number with a prefix B, but not always. The crankcase is VERY different from earlier models.
These models were also offered with the option of a second rear drum brake, as on the English Model B.

English models have the inlet port at the REAR, with the exhaust port on the
left hand side. US models have the inlet port at the FRONT, with the exhaust port on the right hand side.

English models have a brass flywheel with flywheel ignition up to number 3928. This is from an original handbook, but it doesn't say whether this is the chassis number or the engine number. However, from checking on the numbers to hand, it would suggest that this is the CHASSIS number. From that number on, they have a steel flywheel, with a chain-driven magneto situated on a platform which replaced the older flywheel backplate. I know of 7 bikes with this, and 4 of them have very rare small Bosch FB1b magnetos, suggesting that this was the usual magneto fitted. (The other 3 had 3 different makes, and needed a cut-out on the top cover.) I have an FB1b, and also an FB1c which is identical in size. They are small enough to fit under the top engine cover without modification.

English Model A's have both electric and gas lighting, with the electric lamp mounted on the right mudguard stay and the gas on the left. The rear lamp is electric and gas in the same housing.

Early English Model B's have electric lighting with a dry battery for parking lights, and later ones, with magneto ignition, have gas lighting.

US models have Eisemann flywheel magnetos and electric lighting. The later models have 10-pole generators. Early models seem to have had twin lights, later ones a single light mounted on the front mudguard/fender.

Wheelbase 59". Later US models 56".
Seat height 27".
Weight approx 195lbs.
Tyres - US 26" x 3.00" English 26" x 2.5"

English Model C's have the Blackburne 350cc 4-stroke engines fitted, with a Sturmey Archer 3-speed gearbox, and conventional clutch. Dimensions are the same, except for the weight, and the tyres, which are 26" x 3.00".