The Honda CRF series is a line of four-stroke motocross, trail and dual-sport motorcycles manufactured and marketed by Honda. It was launched in 2000 as the successor to the Honda CR series and has grown to cover engines from 50 cc to 449 cc.
Honda CRF series at a glance
| Maker | Honda |
|---|---|
| Launched | 2000 |
| Replaced | Honda CR series |
| Full-size motocross engines | liquid-cooled single, 149–449 cc |
| Trail models | air-cooled, 50–300 cc, F suffix |
| First model | CRF450R |
| CRF250R | from 2004 |
| Enduro versions | CRF450X and CRF250X |
| CycleWorld best motocrosser | CRF450R, 2002–2009, eight years |
| Engine layout | over-square, with short piston skirts |
| F models listed | CRF50F to CRF300F |
Based on one source, the English Wikipedia article on the CRF series. No photograph of a specific CRF model was available among the Commons candidates.
History of the Honda CRF series
Replacing the two-strokes
The CRF line was launched in 2000 as the successor to the Honda CR series. The Honda CRF450R was the first in the series, followed by the CRF250R in 2004; later the CRF450X and CRF250X arrived, both designed mainly for off-road use. The full-size motocross bikes use liquid-cooled single-cylinder four-stroke engines from 149 cc to 449 cc, and the series now includes dual-sport models.
The F trail models
The more trail-friendly CRFs with the F suffix have simple air-cooled engines and range from 50 cc to 300 cc. Honda has made the CRF50F, CRF70F, CRF80F, CRF100F, CRF110F, CRF125F, CRF125FB, CRF150F, CRF230F, CRF250F and CRF300F; the CRF70F, CRF80F, CRF100F, CRF150F and CRF230F have been discontinued. For 2019 the CRF110F, CRF125F and CRF250F gained electronic fuel injection.
Engine technology
CRF engines use an over-square design, with a cylinder wider than the piston stroke, which allows higher engine speeds and lower reciprocating mass for a given displacement. They also use short piston skirts; these cut reciprocating mass but increase piston rocking, which brings more frequent maintenance of pistons, rings and cylinder walls.
Racing success
The CRF450R was CycleWorld’s Best Motocrosser for a record eight consecutive years, from 2002 to 2009, and the family has been a leading seller since introduction.
Design and features
- Two families: liquid-cooled R and X racing bikes, air-cooled F trail bikes.
- Over-square engines: built for high revs and low reciprocating mass.
- Short piston skirts: lighter, at the cost of more frequent servicing.
- Fuel injection: standard on the 2019 CRF110F, CRF125F and CRF250F.
Honda CRF series versions
- CRF450R (2000): the first CRF and the motocross flagship.
- CRF250R (2004): the smaller racing four-stroke.
- CRF450X and CRF250X: enduro versions.
- CRF50F, CRF70F, CRF80F and CRF100F: small air-cooled trail bikes.
- CRF150F, CRF230F, CRF250F and CRF300F: larger trail models.
The CRF series replaced the CR line and sits beside the dedicated CRF450R and CRF150R pages. More Hondas are in the Honda collection.
Sources
- Honda CRF series, English Wikipedia: models, engines, technology, racing record
