The Honda CB-1 is a small, light naked sports motorcycle with a 399-cubic-centimetre (24.3 cu in) straight-four engine, carrying the model code NC27. In contrast to other models of the Honda CB series, the name is written with a hyphen. In some countries it was marketed as Honda CB400F.

The bike was first introduced in 1989 and continued through 1990. Originally developed for the Japanese market, the CB-1 was also available in the United States and Canada. Called a "great motorcycle that never found an audience" and "victims of a difficult market" by Cycle World, the final model year 1990 CB-1s available as leftover stock were offered in 1992 at a $600 discount, for $3700 in the US, which in current money would be $8,033 accounting for inflation.^[2]

The CB-1 engine is similar to the early NC23 models CBR400RR,^[1] with changes to the port lengths and angles as well as smaller valves and lower compression ratio; changes in the primary and secondary gear ratios reduced the 60 mph (97 km/h) first gear down to around 30 mph (48 km/h), making the slightly less powerful CB-1 feel much quicker from a standstill than its sportier sibling, All engines derived from the NC23 block carry the NC23 ID code in the engine number; this includes the NC27, 23, 29, 31 etc., including the VTEC models with chain driven cams. Like many of its stablemates, the CB-1 has straight gear-driven dual camshafts with self-silencing gears to reduce whine.

Cycle World measured the time to cover a 1⁄4 mile (0.40 km) as 13.17 seconds with a final speed of 99.16 miles per hour (159.58 km/h) and the top speed as 118 miles per hour (190 km/h)^[1] Braking distance from 60 to 0 miles per hour (97 to 0 km/h) was 124 feet (38 m).^[1] — saying the bike was "a reincarnation of the standard motorcycle ... the sort of bike everyone rode before sporting riders went replica racer crazy".^[1]

• 
  CB1a
• 
  CB1