MXA’S 2015 HONDA CRF450 MOTOCROSS TEST: EASY DOES IT

2015-crf450-1

Q: FIRST AND FOREMOST, IS THE 2015 CRF450 BETTER THAN THE 2014 CRF450?

A: No. Maybe. In some ways. Barely. Sort of, but not really.

Q: WHAT DID HONDA CHANGE ON THE 2015 CRF450?

A: The 2015 Honda CRF450 has several updates designed to make it more effective as a motocross bike.

(1) Engine. Honda revised the cylinder head, moved the exhaust port from the left side of the cylinder head to the right side, heat-treated the piston, increased the flywheel inertia, and beefed up the gearbox for more durability.

(2) Fuel injection. As is standard operating procedure with modern EFI bikes, the mapping has been changed in both the ignition and fuel modes. Instead of using plug-in couplers like Kawasaki and Suzuki, the CRF450 allows the three modes—stock, mellow and aggressive—to be toggled through from a handlebar-mounted button. Additionally, the throttle return spring has been lightened for more ease of use.

Switcheroo: Honda moved the exhaust port from the left side to the right, upsized the front rotor, reconfigured the Kayaba PSF-2 air forks and added button-actuated maps.
Switcheroo: Honda moved the exhaust port from the left side to the right, upsized the front rotor, reconfigured the Kayaba PSF-2 air forks and added button-actuated maps.

(3) Exhaust. Because of the right-side exhaust port, a new exhaust system was designed. Since there is a lack of room for adequate tuned length, the overall CRF450 system is shorter but compensates with larger tubes and tail pipe diameters.

(4) Forks. Honda did not go with the same Showa SFF TAC triple-chamber air forks that it uses on the 2015 CRF250, but instead stuck with the low-pressure Kayaba PSF air forks from last year. The difference is that the new PSF-2 forks have the compression damping in one leg and the rebound damping in the other. Additionally, the PSF-2 forks have clickers on the fork caps for high- and low-speed damping for both rebound and compression damping on the appropriate fork cap.

(5) Shock. All of the shock’s adjustments—rebound, high-speed compression and low-speed compression—are found on the Kayaba shock piggyback. No more crawling in the dirt to check rebound.

(6) Miscellaneous. The front brake rotor has been up-sized to 260mm. The tire choice is Dunlop Geomax MX52 tires. The clutch cable has been rerouted to lessen pull. Black is the new white on the front brake guide, radiator guards and fork guards. And, of course, there are bold new graphics that aren’t all that bold.

White paper: Honda’s corporate policy on motocross bikes is to make them easy-to-ride—which is code for slow. It’s not white-knuckle fast, more like pink-knuckle fast.
White paper: Honda’s corporate policy on motocross bikes is to make them easy-to-ride—which is code for slow. It’s not white-knuckle fast, more like pink-knuckle fast.

Q: IS THE 2015 CRF450 FASTER THAN THE 2014 CRF450?

A: There isn’t a bike made that isn’t faster than the 2014 Honda CRF450. But somehow, some way, Honda managed to design a new head, fuel-injection mapping, exhaust system, flywheel weight and three-way ignition map switch for the 2015 without blowing the 2014 CRF450 out of the water.

The most noticeable thing about the 2015 CRF450 powerband is that it trades last year’s snappy low-to-mid transition for a slower-revving and mellower pickup at throttle tip-in. Once in the midrange, the 2015 CRF450 power is broader and torquier; however, at no point does it feel faster than the 2014 CRF450. The end product of the 2015’s R&D was that Honda traded low-end throttle response for better power around 7500 rpm.

MXA test riders were torn about the 2015 engine mods. The best aspect of last year’s bike was its quick and aggressive pick-up off idle. That’s gone. In its place is a modestly improved midrange. Sadly, the 2015 CRF450 still peaks at 8500 rpm, and it’s all downhill after that. The power is flat on top and only loses power the higher you rev it.

If you are from the school of thought that 450cc motocross bikes are too powerful for mortal man, this is your bike. It is definitely not too powerful for mortal man­­—or woman. It feels slow, and because of that, MXA test riders could ride it harder. It didn’t scare them with brutal acceleration, blow them off the back of the seat or rev to the moon. It was, as Honda’s engineers must have been aiming for, easy to ride.

Duo: If the advantages outweighed the disadvantages, we’d be all for twice pipes. They don’t, and we aren’t.
Duo: If the advantages outweighed the disadvantages, we’d be all for twice pipes. They don’t, and we aren’t.

Q: HOW DOES THE 2015 CRF450 RUN ON THE DYNO?

A: This bike should stay as far away from a dyno as possible. Dynos don’t like it. The 2014 Honda CRF450 makes the least horsepower of any bike on the showroom floor. Peak horsepower on the 2015 Honda CRF450 is 53.03. That is almost 4 horsepower less at peak than the 2015 Yamaha YZ450F. Even worse, at 10,000 rpm the Honda gives up 7-1/2 horsepower to the YZ450F. Need more bad news? In a comparison of how long each 2015 bike stays above the 50-horsepower mark, the Yamaha, Husky, Suzuki and KTM all stayed in the sweet zone for a range of more than 3400 rpm. The Honda CRF450 only produces 50 horsepower for a range of 2000 rpm. Without meaning to pile on the CRF450, its horsepower peaks at 8500 rpm. That is 500 rpm lower than the KX450F, RM-Z450 or KTM. It is 800 rpm lower than the Husqvarna FC450 and 1500 rpm below the YZ450F. Stats are not the be all, end all of motocross engines, but it’s hard to ignore numbers as pitiful as these.

HONDACRF450ACT

Q: WHAT ABOUT THE THREE MAPS?

A: Five of the six 2015 450 motocross bikes have extra maps built in. Some are accessed with plug-in couplers (Kawasaki and Suzuki), some with dials under the seat (KTM) and some with handlebar-mounted buttons (Husqvarna and Honda). Given the casual approach that the 2015 Honda CRF450 has to covering ground at speed, the MXA test riders immediately began utilizing Honda’s push-button map switch.

To change maps, you must have the engine running. Be forewarned that the rpm must be set very low. We turned the idle up to lessen flame-out, and this blocked the ability to switch maps. To change from the stock map to the mellow map to the aggressive map, you press and hold the button on the right side of the handlebars. When you release the button, it will flash once in succession for the stock map, twice in succession for the mellow map and three times in succession for the aggressive map.

Kaleidoscope: All three shock adjusters are on the piggyback reservoir. No more crawling in the dirt to adjust the rebound.
Kaleidoscope: All three shock adjusters are on the piggyback reservoir. No more crawling in the dirt to adjust the rebound.

What map did we choose? Every test rider chose to race with the stock map. Why? A mellow map on a 2015 Honda CRF450 is pointless, because Honda’s stock map would be the mellow map on the yellow, green, blue, orange or white bikes. The aggressive map wasn’t any faster, but it was hyperkinetic at throttle tip-in. It was jerky and jumpy. It did rev out farther, but on a CRF450, this is meaningless, because the farther it revs, the less horsepower it makes. Thus, we stuck with the stock map.

To cross-check the MXA test riders’ opinions, we dyno tested all three maps. Surprise! The stock CRF450 map (one flash) made 1 to 2 more horsepower than the other two maps at every rpm on the complete power curve. The mellow map (two flashes) traced the aggressive map (three maps) from idle to 7800 and then fell off quickly.

If you like to see flashing lights, go ahead and play with the button, but after you are done being mesmerized, put it back on the stock setting.

Q: WHAT DO YOU NEED TO KNOW ABOUT THE 2015 CRF450?

A: Here are a few pertinent Honda CRF450 factoids.

Weight. The Honda is not just the lightest 450, it is also the lightest-feeling. Compared to its overweight competitors, the CRF450 feels like a CRF250 in motion.

PSF-2 forks. The revised Kayaba air forks are simpler to work with than the Showa SFF TAC air forks, but Honda doesn’t make it too easy to access the high- and low-speed damping adjusters, which are hidden by the handlebars. If you don’t have a disc-style screwdriver, you will have to angle in with a long skinny flat-blade screwdriver.

Heft: The 2015 Honda CRF450 feels light, and not just once in motion. It is the lightest 450 in the Big Six.
Heft: The 2015 Honda CRF450 feels light, and not just once in motion. It is the lightest 450 in the Big Six.

Power. The powerband is short. It does its best work below 8500 rpm, and after that it is a dead fish. You need to short-shift at peak. Be forewarned: don’t short-shift before peak because the CRF450 doesn’t make enough power to pull a tall gear at low rpm. And, don’t shift after peak, because every rpm after 8500 is a losing proposition.

Exhaust pipe. It sticks out like an Oahu-to-Maui outrigger canoe.

Gearing. We geared it down from 48 teeth to 49 teeth to try to maximize what’s there, but if “pleasant” is your game, leave the gearing alone.

Clutch. It has a very spongy feel, and every MXA test rider believed that if they used it, they would lose it. We ran stiffer clutch springs immediately.

Front brake. Honda up-sized the front rotor to 260mm, but if you thought that was going to get this bike on par with the KTM, you are wrong. The CRF450 brake has more oomph than before, but not as much as KTM’s.

Twice pipes. In our experience, single-sided exhaust systems are lighter, run better, cost less and are easier to repack. Honda obviously believes in the twice-pipe idea—even if no one else does.

Flame-out. Any bike can flame-out under hard braking into a turn, but the Honda is the absolute best at it. For 2015, the engineers added more inertia to the flywheel to help alleviate the problem. If you are still afraid, turn the idle up (after you have set the ignition map).

Shock linkage. We run a longer aftermarket shock linkage. The benefits of dropping the rear of the CRF and stiffening up the initial part of the stroke with a longer link arm are undeniable. Since the longer link rotates the bell crank into a stiffer position, the longer link increases low-speed resistance and holds the rear higher in the bumps.

Q: DOES THE 2015 CRF450 HANDLE BETTER THAN THE 2014 MODEL?

A: Surprisingly, without any geometry changes to support the assertion, we think the 2015 feels better than the 2014. This is probably a side effect of reducing the bark off idle, improving the overall feel of the front forks and the broader midrange.

Turn initiation is the CRF450’s best trait. It feels like a red Suzuki at the entrance to turns. Yes, it is twitchy in the rough, but as Suzuki has proved, you have to give to get. We turn the HPSD steering damper all the way in to help calm the front end at speed.

HONDA15ACTION

Q: WHAT DID WE HATE?

A: The hate list:

(1) Bad stuff. No need to delve deeper into what we don’t like. What we want is simple: more horsepower, a broader powerband, a workman-like clutch, a single-side pipe (that is tucked in) and maps that make a positive difference.

Q: WHAT DID WE LIKE?

A: The like list:

(1) Setup. If this bike made 56 horsepower, moved the peak up 500 rpm, didn’t go flat on top, had a single exhaust system and was equipped with a stronger clutch, it would be the bike of the century. It is very well made, oozes trickness, has suspension that is ballpark and has a lightweight, graceful and agile feel that no other bike offers. It is the most fun to ride.

Q: WHAT DO WE REALLY THINK?

A: The 2015 Honda CRF450 is the 2013 model with more complex air forks. Yes, Honda did make updates and mods, but basically Honda is treading water by virtue of its corporate policy that race bikes should be slow.

Power: Honda revised the CRF450 engine, but the dyno didn’t notice.
Power: Honda revised the CRF450 engine, but the dyno didn’t notice.

MXA HONDA CRF450 SETUP SPECS

This is how we set up our Honda CRF450 for racing. We offer it as a guide to help you find your own sweet spot.

KAYABA PSF-2 FORK SETTINGS
Honda ran Kayaba’s low-pressure PSF air forks in 2013 and 2014, but for 2015 they are switching to PSF-2 air forks. They are basically a blend of WP 4CS forks (in that the rebound is in one fork leg and compression in the other) and the previous PSF air forks. Unlike Showa SFF TAC forks, which run about 170 psi, PSF-2 forks only use 35 psi. The twist is that Kayaba added both high- and low-speed compression and rebound damping on the top of the fork caps.  The PSF-2 forks are an improvement over last year’s PSF forks and much easier to live with than SFF TAC air forks. For hardcore racing, these are MXA’s recommended 2015 Honda CRF450 fork settings (stock settings are in parentheses):
Spring rate: 35 psi
Oil height: 92mm
Hi-compression: 14 clicks out (11 clicks out)
Lo-compression: 12 clicks out
Hi-rebound: 10 clicks out
Lo-rebound: 10 clicks out (9 clicks out)
Fork-leg height: 5mm up
Notes: The high- and low-speed clickers are not easily accessible because the handlebars block them. This makes adjusting them very difficult. The solution is to get a flat disc-style screwdriver from Noleen (www.noleenj6.com) or Pro Circuit (www.procircuit.com).

KAYABA SHOCK SETTINGS
Honda has had decent suspension for the last five years, although most MXA test riders tend to go a little stiffer on the shock spring. For hardcore racing, these are MXA’s recommended 2015 CRF450 shock settings (stock settings are in parentheses):
Spring rate: 5.7 kg/mm (5.5 kg/mm)
Race sag: 100mm
Hi-compression: 19 clicks out
Lo-compression: 15 clicks out
Rebound: 4 clicks out
Notes: High-speed compression used to be measured in the number of turns of the big dial on the shock’s piggyback, but now it is done in clicks. Since all of the damping adjusters are on the piggyback, you must recognize the colors of the identical-looking clickers. Red is rebound, blue is high-speed compression, and silver is low-speed compression.

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