| Attribute | Value |
| General |
| Production from | 2010 year |
| Make | GAS GAS |
| Model | GAS GAS Halley 125 2T |
| Category | Trial |
| Engine and transmission |
| Engine type | Single cylinder, two-stroke |
| Valves per cylinder | Add |
| Fuel system | Carburettor. 26 mm |
| Engine details | Add |
| Displacement | 124 cm³ |
| Power | Add |
| Max RPM | Add |
| Fuel consumption | Add |
| Cooling system | Liquid |
| Transmission type,final drive | Chain |
| Torque | Add |
| Bore | 54 mm |
| Stroke | 54.5 mm |
| Gearbox | 6-speed |
| Greenhouse gases | Add |
| Fuel control | Add |
| Emission details | Add |
| Driveline | Add |
| Ignition | Add |
| Clutch | Multiple disks in oil bath, hydraulic |
| Lubrication system | Add |
| Compression | Add |
| Exhaust system | Add |
| Chassis |
| Front suspension | Fork, 41 mm. |
| Rear suspension | One-piece aluminium swing arm |
| Front brakes | Single disc. Twin piston caliper. |
| Rear brakes | Single disc. Single-piston |
| Diameter | 220 mm |
| Frame type | Deltabox*, made with Cromoly tubing. Aluminium swing arm. |
| Front tyre | 80/90-21 |
| Rear tyre | 110/80-18 |
| Seat | Add |
| Wheels | Add |
| Front wheel travel | 255 mm |
| Rear wheel travel | 246 mm |
| Trail | Add |
| Rake (fork angle) | Add |
| Other |
| Battery capacity | Add |
| Starter | Kick |
| Color options | |
| Carrying capacity | Add |
| Light | Add |
| Instruments | Add |
| Electrical Voltage | Add |
| Dimensions |
| Wheelbase | 1,460 mm |
| Kerb weight | 107 kg |
| Dry weight | 99 kg |
| Power/weight ratio | Add |
| Overall height | Add |
| Overall length | Add |
| Overall width | Add |
| Seat height | 945 mm |
| Alternate seat height | Add |
| Ground clearance | Add |
| Front percentage of weight | Add |
| Rear percentage of weight | Add |
| Performance |
| Top speed | Add |
| Acceleration 0-100 km/h | Add |
| Length | Add |
| Reserve fuel capacity | Add |
| Fuel capacity | 7.4 l |
| Oil capacity | Add |
| Width | Add |
| Height | Add |