Don't let the engine size fool you. The 150cc dirt bike actually rides pretty tame and most consider this one a play bike for the experienced or an excellent starter for beginners.
Though KTM manufactures a 2-stroke version of the 150 primarily for racing Motocross, the 4-stroke version ranks most popular for those looking to buy. The 150cc 4-stroke doesn't rip, at least in terms of what you need on a Motocross track like the 2-stroke, instead, steady as she goes, the 150 4-stroke offers more bottom-end power ideally suited for trail riding.
What Is a 150cc 4-Stroke Dirt Bike?
A Honda.
Huh? Currently, Honda makes the only 150cc 4-stroke dirt bike in the CRF150R. (KTM owns the monopoly on the 2-stroke version.) At the risk of getting too far into the weeds, let's break this down a bit for those looking to buy a 150 and now realizing they only have two choices.
The 85cc 2-stroke dirt bike presents a popular counterpart to the 150 4-stroke. Both look similar in size but the 85, with its top-end power, gives the racer more bang for the buck in terms of desired speed. All that to say, a 150cc dirt bike introduces the beginner adult rider to the wide wide world of dirt bikes while giving the veteran a fun, easy to handle ride when taking a break from the rigors of racing.
The 150cc engine size points to the power output in cubic centimeters, a unit of volume that describes the engine displacement or combustion chamber where the fuel and air mix to produce power. The more fuel and air, the greater power. The 150cc offers far less power than a 250 or 450 but much more than a 50cc.
Well, what about that 85?! Faster? Two-stroke vs. 4-stroke, my friend. Plus, engine displacement alone doesn't determine a dirt bike's top speed. Other factors such as engine design, gearing ratios, and weight play significant roles.
Therefore, those looking for a competition bike, i.e. racing Motocross, ride the 85 while those who want a trail bike or to zip around their big back yard, stick with the 150. Once wide open, the 85 and 150 run neck and neck but the 85 gets such a big jump at the start the 150 never catches up. That means the Honda CRF150R competes alongside the 2-stroke 85cc in MX competition.
Wait, what about the 125!? Good call, my friend. Again, we have a difference in power because of the 2-stroke vs. 4-stroke thing. The 125 2-stroke puts out three times the horsepower than a 150 4-stroke. Race them side-by-side the 125 grabs the Holeshot over the 150 every single time. Thus, the reason why pros practice on a 125 2-stroke to hone their skills and use the 150 4-stroke for fun.
The 4-stroke Honda CRF150F falls into a similar category as the 4-stroke Kawasaki KLX140, CRF125F, Yamaha TTR125L and the Suzuki DRZ125L. All of these mild-in-power 4-stroke models trend towards great beginner dirt bikes for trail riding, These 4-stroke 125s pretty much run side-by-side with the Honda 150 4-stroke. Now that we got that out of the way...
MotoSport-sponsored rider Danny Robinson on his TTR125 converted to a 150
Factors Influencing the Speed Capabilities of a 150
The gearing of a 150cc dirt bike provides a balance between acceleration and top speed, making it suitable for various riding conditions and beginner riders. A new rider probably won't loop out on a 150 as you likely would on an 85 if you pinned it at the start.
Like any sized bike, terrain plays a huge role in how fast you ride. Arguably, the 150, ideally suitable for trails, likely reaches top speeds for longer periods of time than most other dirt bikes. Desert trails, hard pack trails and other straightaways that make trail riding so fun let you get up to speed, and keep it there. But throw in slippery conditions, sharp turns and obstacles like logs, rocks or maneuvering in between trees, you get natural speed bumps that slow you down.
Beginner riders will have a hard time reaching top speeds until they get comfortable on the bike and the overall weight placed on the bike also helps bog it down. A rider's body weight plus all the safety gear worn contributes to the bike's ability to reach its high-speed potential. Elsewhere, aftermarket parts not only reduce weight but help in overall performance, including top speed.
150cc Dirt Bike Top Speed
Under normal circumstances, the top speed of a 150cc dirt bike (i.e. the Honda CRF150F) ranges between 40 and 60 mph. Skill, hard terrain with room to run and upgrades get you to the higher end of that spectrum but a stock bike under the control of a beginner rider speeds along in the low 40s. But, ride a modified 150 on pavement with skill and expertise expect to surpass 60.
Compared to the popular 250 and 450, the power and overall top speed of a 150cc dirt bike ranks on the lower end of the scale making this a great starter bike for those who missed the riding boat during their younger years.
