In 2007 Honda revolutionized the stagnant mini class by introducing the first four-stroke competition mini into the small bore ranks. Borrowing technology from its proven 250 and 450 models, Honda released the CRF150R. Just like the larger four-strokes, the 150 delivers a torquey, user-friendly motor that puts the power to the ground in a way unlike any of the current 85cc two-strokes.
The CRF150R has a serious advantage at the motocross track. The high revving four-stroke delivers strong, smooth and usable power all the way through its power curve. The motor is so strong that the AMA determined the bike would not be legal to compete in the 85cc class in AMA-sanctioned events. The CRF is however eligible in the supermini class, as well as in the 85cc class at other, non AMA-sanctioned events. The benefits of the CRF150R motor stretch far beyond the MX track, though. Trail riders and weekend warriors will find the user-friendly motor much to their liking.
Honda left the CRF150R unchanged for 2008 and 2009. In 2010 and 2011 they didn’t release new models, but instead continued selling the 2009 model. Finally, five years after its original release, Honda has decided to update the little thumper for 2012 and address any flaws that the previous model may have had. We got a first ride on the new CRF during the press intro back in September, and came away very impressed with the new 150 and its changes. Our mini test rider was so impressed with the new CRF that we begged Honda to hold onto the new bike and further test the machine at a variety of tracks and trails to see if it’s really as good as he first thought.
The Standard Stuff
The 2012 CRF150RB is legal in the supermini class but it has been banned from the 85 division for AMA-sanctioned events.
Just like the previous model, the new CRF150 is available in two sizes. The CRF150R is the standard-sized mini with a 14-inch rear wheel and 17-inch front. The CRF150RB, or “expert,” is designed for taller riders and features a 16/19-inch wheel combo. The larger wheels on the expert version give it a slightly taller seat height of 34.1 inches compared to the standard version at 32.8. Other dimensional differences include the wheelbase and ground clearance. The standard model ends up with a 49.6-inch wheelbase and a ground clearance of 11.9 inches. The expert version increases to 50.6 inches for the wheelbase and 13.2 inches for ground clearance.
Both models utilize the same Showa cartridge fork with the expert dropping the tubes in the triple clamp to accommodate the larger front wheel. The result is 10.8 inches of front travel on both bikes. The big-wheel sees a slight increase of travel in the rear with 11.1 inches, up from the standard 10.7 on the R model. The expert also ends up with a slightly increased rake and trail. Honda claims a four-pound weight difference between the two with our fully fueled expert model weighing in at 188 pounds.
The engine, carburetor and transmission are identical between the two. Both bikes use a 149cc liquid-cooled single-cylinder four-stroke engine with a bore and stroke of 66mm x 43.7mm. Compression ratio is 11.7:1. Up top is Honda’s Unicam valve train with a four-valve cylinder head using 26mm intake and 22.5mm exhaust valves. All four valves are steel. Rounding out the package is a close-ratio five-speed transmission.
While the new 2012 CRF150 may look similar to the previous generation, Honda has made a number of significant changes to the mini ripper. The original machine had finicky carburation and was hard to jet correctly, often resulting in a small flat spot in the otherwise linear power curve. Honda engineers addressed this hiccup by giving the 2012 model a new 32mm Keihin FCR style flat-slide carburetor and an improved “direct push” accelerator pump.
Changing the carburetor was a major step in improving the 150, but Honda didn’t stop there. Honda redesigned the cylinder head, piston and camshaft to give the CRF improved power, torque and drivability throughout the powerband. In addition to improving the engine and carburation, the new 150 also features some suspension enhancements as well. The Showa suspension received new valving front and rear to improve the action on small bumps while retaining it’s large bump performance.
Aesthetically, the bike received updated graphics to match its larger siblings. The similarities stop there though, as the 150 does not get an aluminum frame or sleek white rear fender. While these types of changes would have been cool, they would have added to the already hefty price tag.
Our test rider is happy that the little four-stroke is easy to start whether hot or cold. There’s no issue recovering from a crash or stall.
After our first ride at Piru MX in SoCal, we took the bike to a number of other tracks both in California and back home in Oregon. We not only gained feedback during practice days, but also put the CRF through the paces in an actual race environment by entering it in the 85cc 12-13 year old class at our local MX track. We then embarked on some woods riding at various elevations to see if the carburation encountered any problems as the altitude changed and to see how the motor and suspension performed during slower, more technical riding. In addition to gaining rider feedback, we also performed a number of non-subjective performance related tests including dyno runs, sound testing and a fully wet weigh-in.
For testing duties we retained the services of 12 year-old Luke Chamberlain, who also performed the initial riding impression. Luke has eight years of riding experience and five years of racing under his belt. He currently races a two-stroke 85cc, but since throwing a leg over the 150 at Piru, he has yet to want to get back on his pre-mixer.
Getting a carbureted four-stroke to start can often be a challenge. Fortunately, it doesn’t get much easier than firing up the 150. We struggled a little at first during cold starts until figuring out that the bike usually needs a little gas in order to fire. With the choke on, we give the bike three good twists of the throttle to get some gas flowing and it fires in one or two kicks. If it doesn’t start on the first kick, a little throttle during the second kick usually bring the CRF to life.
The 150 also starts very easily when hot, although it requires the bike to be in neutral. Chamberlain also commented that it’s sometimes difficult to find neutral. With the hot start lever engaged, he can usually bring the Honda to live with just a kick or two, as long as he takes the time to get the CRF out of gear.
The Heart of the Beast
The CRF150R is definitely in a class of its own, and the high-revving four-stroke engine is what separates it from the rest of the pack. Our mini test pilot instantly fell in love with the smooth, torquey motor and has only grown fonder with the increased seat time.
Our mini racer also found the carburetor and engine enhancements very effective. The throttle response is quick and power delivery smooth and linear at every location we tested. He comments that the bike pulls hard and does so as soon as the throttle is twisted, no matter what the current rpm. He feels the CRF has a huge advantage over the 85’s especially when driving out of tight corners. While the two-stokes are searching for the power band and slipping the clutch, the 150 is putting the power to the ground.
It took Luke a few rides to break his old two-stroke habits and stay off the clutch exiting corners. Once he finally figured out that all he needed to do was apply the gas, his corner speed began increasing dramatically. The same was true out in the woods where he was able to bog the engine much lower that his two-stroke and get back on the gas, with little or no help from the clutch, and instantly claw his way up any terrain.
Our dyno runs on the DynoJet dyno at Hansen’s Motorcycles echoed our tester’s input with only one small deviation. On the dyno, when the throttle is first hammered to full lock at about 4000 rpm, the CRF shows a small flat spot before quickly building power. Once the revs reach about 6000 rpm, the engine produces a nice smooth curve all the way to the rev limiter at 14,000. Our test unit cranks out a peak horsepower of 21.6 HP at 12,600 rpm and 9.73 lb-ft of torque at 9,800 rpm. The small flat spot was unnoticed by our test rider, mostly due to the fact he rarely drops the rpm down to 4000 during normal riding.
We measured sound output with the SAE J1287 20-inch stationary test. At 7,000 RPM, our sound meter read 98 decibels. We thought this was a little loud and would like to see if an aftermarket exhaust could quiet the beast down a bit. We would also like to get a silencer that uses a spark arrestor insert for woods riding.
A stock 56-tooth rear sprocket is a bit short for wide-open tracks, but it works well on tight MX layouts and in the woods.
While the CRF’s smooth power is the standout feature of the CRF, our test pilot is also very impressed with the clutch and transmission on the 150. The clutch especially grabbed his attention due to its buttery pull and awesome feel during disengagement. We noticed a huge improvement in his starts at the MX track, not only due to the bike’s ability to pull down the start straight, but also because of his ability to finesse the clutch during launch.
The five-speed transmission also performs flawlessly with no missed shifts or false neutrals. The final gearing on our expert model uses a 56-tooth rear sprocket, as opposed to the 50-tooth on the standard model. On fast, wide-open tracks we thought the stock gearing might be a little short, although we never found a situation that topped out in fifth, even though first gear was rarely ever used. Out in the woods the short gearing works perfectly and is well suited for tight, technical riding, while still giving the bike some legs when the trail opens up.
Soak it up
For 2012, Honda gave the Showa suspension new valving front and rear, claiming improved action over small bumps while retaining its large bump performance. Our 95-pound test rider was pretty happy with the new suspension and really likes how well it soaks up big landings. We set the sag at 105 mm and left the clickers in the stock positions for the first few rides until the suspension was fully broke in. Luke thought the fork worked well, although it’s a little harsh and jittery when accelerating through fast chatter. After getting some time on the bike we decided to soften up the compression slightly both front and rear. Since most of the tracks we were riding were pretty fast and hard pack we sped up the rebound on both ends slightly as well.
New suspension valving makes the CRF a great jumper. We haven’t had any problems with big impacts or small chop.
Our fully fueled big-wheel 150 weighs 188 pounds, which is about 30 lbs. more than a small-wheel 85cc, but once in motion our test rider said the additional weight doesn’t bother him. He considers the bike fairly nimble and easy to turn in. A highlight of the CRF’s handling is how well it tracks through the corner and our tester’s corner speed has actually increased since riding the 150. We did experience some headshake when accelerating through hard-edged chop. To alleviate this we dropped the fork tubes 5mm in the clamps to give the bike a little more stability.
One area where the additional weight comes into play is during technical riding in the woods. Along with the taller seat height, the added weight makes the CRF a little harder to manhandle in slow situations.
Our 5’3” test rider found the CRF’s ergo’s perfectly suited for his stature. He’s able to touch with both feet and the tall bars allow him to stand comfortably. As with most minis, the stock bars are steel and bent during the first decent crash our tester encountered.
The stock footpegs are decent in size, although we would prefer a slightly larger platform. The pegs are nice and open, allowing dirt to clean out easily, but we did have a problem with the left peg folding up and getting stuck after a fall. Our
left peg has a slight variance in its tolerances, which allows it to fold too far and wedge the return spring between the peg and the mounting bracket. The small flaw results in big problems when racing as our 12 year-old rider is not able to dislodge the peg by himself.
We also bent the rear tube of the sub-frame during a pretty hefty crash. The steel sub-frame is constructed with lateral support, but unfortunately couldn’t hold up to the cartwheel we subjected it to. We were able to easily bend the tubes back into place and thankfully the sub-frame is removable in case the resulting damage is beyond repair.
The rest of the componentry is be top notch and Honda’s fit and finish is second to none. Thus far we have only had to perform basic maintenance on our test bike. Like the larger CRF’s, the 150 separates the engine oil from the transmission oil. Checking the engine oil is performed with a dipstick, though a sight window would be even simpler. The air box is a little tight, although it’s easy to properly secure the filter to the air box mount thanks to the clips on the air filter cage that help align it with the air box. Like the larger CRF’s, getting the filter on the cage can be a bit of a struggle.
In the end
Overall we continue to be impressed by the new CRF150RB. Our tester can’t say enough about the Honda’s engine. The updates to the carburetor have solved the issues with the previous model, although some fine tuning of the jetting would likely get rid of the hesitation we saw on the dyno. Aside from a few small components, the CRF150RB has been bulletproof and we haven’t encountered any mechanical problems. Most importantly the CRF is a blast to ride and we can’t keep our test rider off the bike. If there’s a downside to the CRF it has to be the pricetag. The standard 150R retails for $4990, about $1000 more than a comparable 85, and the expert model increases the cost to $5090. After riding and racing the CRF, though, we think the added cost is worth the result. If you can’t afford the CRF, just make sure you never let Jr. test ride one, because eventually you’ll end up buying it.
Our mini rider can’t get enough of the new CRF, and to avoid a major temper tantrum, we’re not giving it back yet. Look for future articles on the CRF150RB where we turn an already stellar motorcycle into a mini riders dream bike. We’ll start with some basic component upgrades, further dial in the suspension and jetting and finally, try to get even more power out of the already potent CRF.