| KTM 640 Adventure | |
| Manufacturer: | KTM |
| Production: | 1998-2007 |
| Successor: | KTM 690 Enduro |
| Class: | Dual-sport |
| Engine: | 620cc single cylinder, 4-stroke, Mikuni BST40, Pressure oil lubrication |
| Bore Stroke: | 101mm78mm |
| Compression: | 11.7:1 |
| Power: | 54hp/7000rpm |
| Torque: | 55Nm/5500 rpm |
| Ignition: | Kokusan DC-CDI |
| Transmission: | 5 gears, dog clutch engagement |
| Frame: | Chromium-molybdenum, power-coated |
| Suspension: | Front: WP USD 48mm fork, Rear: WP monoshock with Pro Lever Linkage |
| Brakes: | Front: Dual 320 mm disc (from 2004); Rear: Brembo 1-piston floating caliper, 220 mm disc |
| Tires: | Front: 90/90-21"; Rear: 140/80-18" |
| Rake Trail: | 62.5° |
| Wheelbase: | 1510mm ±10mm |
| Seat Height: | 945mm |
| Dry Weight: | 158kg (348lb) |
| Fuel Capacity: | 25.5L, 3.5L reserve |
| Related: | Duke 640 |
The KTM 640 Adventure is a dual-sport motorcycle made by KTM from model years 1998 until 2007.
The bike featured a single cylinder engine, 21" front and 18" rear wheels and a large fuel tank as standard. It experienced a number of minor changes over its lifespan.
In 1997 KTM introduced the 620 Adventure with a 609 cc engine. The bike received a new 625 cc engine for the 1998 model year and was renamed the 640 Adventure-R.
For model year 2004 it experienced noticeable changes with a low front fender, twin front brake discs and the primary color changing from silver to orange.
Production ceased at the end of the 2007 model year after no further displacement changes.