Honda CRF series
Encyclopedia
The Honda CRF series is a line of four-stroke
motocross
and trail motorcycle
s manufactured and marketed by Honda
.
The CRF line was launched in 2002 as a successor to the Honda XR series
. The full sized motocross
bikes are equipped with liquid-cooled, single-cylinder four-stroke engines that are available from 149 cc to 649 cc. They now have dual-sport motorcycles. The entry-level CRF's have simple air-cooled engines, and are available from 50 cc to 230 cc. The Honda CRF450R was the first in the series, followed with the CRF250R in 2004. Further down the line, the CRF450X and CRF250X bikes emerged, both designed for mostly off-road use. They are considered among the best motocrossers of their class, and have been a leading seller since their introduction.
Overall the new high-performance four-stroke engines in Honda's motocross bikes produce much more power per pound than older generation engines and rev more freely; in the quest for more power, longevity is reduced and maintenance is increased.
As of 2007, the CRF X series includes the 250X and the 450X. These bikes are electric start and are still considered race bikes, albeit for off-road rather than motocross. Differences from the R models include lighting, electric start, suspension settings, engine tuning and exhaust tuning for more torque, larger fuel tanks and wider-spread gear ratios.
As of 2008, the CRF L series includes the 230L. Since this motorcycle is a dual-sport motorbike
it is street legal with everything included but can still make its way on the dirt. It has a completely different frame and engine from Honda's CRF230F. Everything else is set up much differently from the F series. Both 230s have electric starts. Outside of the United States the CRF230L is marketed as the XR230L.
As of 2008, the XR R series includes the 650R (liquid-cooled), 650L (air-cooled). The 650L is electric start and is modeled after the old school XR600/NX650.
Four-stroke cycle
A four-stroke engine, also known as four-cycle, is an internal combustion engine in which the piston completes four separate strokes—intake, compression, power, and exhaust—during two separate revolutions of the engine's crankshaft, and one single thermodynamic cycle.There are two...
motocross
Motocross
Motocross is a form of motorcycle sport or all-terrain vehicle racing held on enclosed off road circuits. It evolved from trials, and was called scrambles, and later motocross, combining the French moto with cross-country...
and trail motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
s manufactured and marketed by Honda
Honda
is a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...
.
The CRF line was launched in 2002 as a successor to the Honda XR series
Honda XR series
The Honda XR series motorcycles are a range of single-cylinder four-stroke off-road motorcycles that were designed in Japan and assembled all over the world. The series is gradually being replaced by the similar CRF series. Some of the XR series came in two versions, R and L...
. The full sized motocross
Motocross
Motocross is a form of motorcycle sport or all-terrain vehicle racing held on enclosed off road circuits. It evolved from trials, and was called scrambles, and later motocross, combining the French moto with cross-country...
bikes are equipped with liquid-cooled, single-cylinder four-stroke engines that are available from 149 cc to 649 cc. They now have dual-sport motorcycles. The entry-level CRF's have simple air-cooled engines, and are available from 50 cc to 230 cc. The Honda CRF450R was the first in the series, followed with the CRF250R in 2004. Further down the line, the CRF450X and CRF250X bikes emerged, both designed for mostly off-road use. They are considered among the best motocrossers of their class, and have been a leading seller since their introduction.
Engine technology
Honda employs advanced four-stroke engine technology in their 250cc and 450cc bikes. The engines in these bikes use technology developed in Formula One racing engines. Honda uses an over-square engine design, this means that the diameter of the cylinder is larger than the stroke of the piston. This allows for higher engine speeds and a reduction of reciprocating mass. Another technology that is used is short piston skirts. The "skirt" area of the piston is the portion on the side of the piston which comes into contact with the cylinder wall and aids piston stability. While the introduction of the shorter skirt on the piston helps to reduce reciprocating mass, it also leads to more "rocking" of the piston, or minute unwanted rotation of the piston around the axis of its wrist pin. This leads to more frequent maintenance intervals for the pistons, piston rings, and cylinder walls.Overall the new high-performance four-stroke engines in Honda's motocross bikes produce much more power per pound than older generation engines and rev more freely; in the quest for more power, longevity is reduced and maintenance is increased.
As of 2007, the CRF X series includes the 250X and the 450X. These bikes are electric start and are still considered race bikes, albeit for off-road rather than motocross. Differences from the R models include lighting, electric start, suspension settings, engine tuning and exhaust tuning for more torque, larger fuel tanks and wider-spread gear ratios.
As of 2008, the CRF L series includes the 230L. Since this motorcycle is a dual-sport motorbike
Dual-sport
A dual-sport, colloquially known as "dualie" or an "on-off road bike" is a type of street-legal motorcycle that is designed for both on and off-road use. The terms All-road and Dual-purpose are also used...
it is street legal with everything included but can still make its way on the dirt. It has a completely different frame and engine from Honda's CRF230F. Everything else is set up much differently from the F series. Both 230s have electric starts. Outside of the United States the CRF230L is marketed as the XR230L.
As of 2008, the XR R series includes the 650R (liquid-cooled), 650L (air-cooled). The 650L is electric start and is modeled after the old school XR600/NX650.