| MODEL | VELOCETTE MSS SWINGING ARM 1954 - 1968 |
| Year | 1954 - 1968 |
| Engine Type | Single cylinder, four-stroke, OHV, aluminium head |
| Displacement / Capacity | 499 cc / 30.4 cu in |
| Bore X Stroke | 86 x 86 mm / 3.4 x 3.4 in |
| Compression Ratio | — |
| Cooling System | Air |
| Max Power | 17 kW / 23 hp @ 5000 rpm |
| Max Torque | — |
| Ignition | — |
| Induction | — |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 4-speed, foot change |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Brazed lug chrome-moly tube, single downtube duplex cradle |
| Front Suspension | Veloce telescopic forks, hydraulic damping |
| Rear Suspension | Swinging arm, twin adjustable Woodhead Monroe or Girling units |
| Front Brakes | 7.5 in / 190 mm SLS drum |
| Rear Brakes | 7 in / 178 mm SLS drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 31 in / 787 mm |
| Wheelbase | 54 in / 1372 mm |
| Ground Clearance | 6 in / 152 mm |
| Dry Weight | 170 kg / 375 lb |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.25 x 19 |
| Rear Tyre | 3.25 x 19 |
| FUEL SYSTEM | |
| Fuel Capacity | 2.5 gallons |
| Fuel Consumption | — |
| Top Speed | 80 mph / 130 km/h |
In 1953-54 the MSS was redesigned with a light-alloy 499 cc engine with square 86 x 86 mm dimensions and the shorter swinging-arm frame from the MAC. It was a relaxed, flexible 500 single for solo and sidecar use, with the sportier Venom appearing in 1955 alongside it. Later examples gained a squarer tank and optional glass-fibre enclosures.
