We Ride the JCR Honda CRF450X Race Bike

Going Racing On The 2019 Honda CRF450X

Photos by Gabe Adams and Jimmy Lewis

The 2019 CRF450X is a brand new bike and we’ve really found a sweet spot for ours in the stuff that made the “X” famous, the desert. The bike even proved itself in the rebirth of motorcycles famous Mint 400 with Ricky Brabec and Kendal Norman taking the overall victory on the JCR backed Honda. DBT was lucky enough to get a quick spin aboard the race bike prior to the event in a shakedown test. We were wanting a benchmark for our long-term test bike and we wanted to see all the potential available.

First of all, the JCR bike is evolving and evolving quick. From early testing 11-times Baja champion Johnny Campbell knew the new X was going to be a better off-road race bike than the older X or even the current CRF450R or RX. Mostly because of the chassis but also due to the six-speed transmission and engine durability which come from the bike also sharing the street going L platform which must meet a whole nother level of longevity in Honda world. So what does it take to turn the bike from an ordinary fun dirt scooter to a full-blown racer? Read on.

Everyone is wondering about the engine and what can be done to it to make it faster. With a locked ECU there isn’t a ton that can be done in making a racer without addressing that. For JCR, special parts are not an issue and they have a works ECU on the race bike that allows re-programming just like the factory supercross bikes. So right from the start, regular riders are going to have to turn to aftermarket solutions, which are coming. DBT has turned to JD jetting to get the fuel mixture right on our bike after we installed an exhaust system. JCR uses Pro Circuit systems that were custom built just for this race as they are still tuning and looking for more and more power. Rumor has it the race bike was in the higher 50’s for horsepower and there is still more available. Right now the building is slow as learning the limit for durability is better done in testing and not at the race.

On the engine the biggest change is the switch to a RX cylinder head. This is obvious since the integrated thermostat housing and exhaust gas air injection X head is gone missing on the RX part. Yes, the race bike does not need all those emissions and safety parts. But since the X has a unique piston (two compression rings) and the cases and cylinder height are a little different from the RX, those parts remain standard X for now. But we are told that the internal shapes of the ports inside the head and the valves are the same between the two parts. The cam is a little different. The intake followers are also different. This mod drops a little weight and simplifies the hoses. If anything the power gain comes from the cam and additionally the port and polish Pro Circuit puts on it.

You can do a lot but the four-stroke is basically pumping air. To get more in there the standard air box is heavily modified by removing the upper portion which also has the good side effect of making filter changes a snap once the seat is off.

The bottom end remains pretty standard and will likely stay that way. The stock plastic covers are gone and Hinson provides some parts related to the clutch. Even the final drive gearing is stock, no need to “gear to the moon” like was common on the five-speed transmission.

The engine performance is a world away from the totally stock bike and a pretty substantial jump up from even our long-term bike. Not necessarily in top-speed, the race bike went 104 and our bike topped at 101 via GPS. But in the way the bike picks up speed and how hard it accelerates. There is a distinctive increase in the snap the bike has with every crack of the throttle and the torque it pulls with, especially through the mid-range. The rev cut of the race bike is still in a very safe place and it makes power all the way up there even sounding a bit like an older YZ250F when it is screaming near the limiter. And with the much louder muffler you really hear this bike coming. The sound is for racing and not for the trails but it does sound good from a distance if you like a sweet race bike noise.

The eye-candy factory Showa A-kit suspension is one of the most drooled over parts. For most they would be overkill because kit suspension doesn’t just work better off the shelf. It takes tuning and a lot of it to get set up for the rider’s specific needs. And during the day JCR was testing between two different sets, clicking and fine tuning was being done. Earlier the full revalve and teardown sessions had honed the setting to where it was. These components had previously been pre-developed on the RX during last year so there was history in them. But everyone still wants to know how the suspension really works.

On the first bike I rode, the National Hare & Hound bike, my initial impression was very positive. Unlike most race setups the bike was not overly stiff and I got a really good feel for the wheels, especially the front wheel, on the ground. Knowing that Ricky likes a very compliant ride, this didn’t surprise me. The bike also had a pretty progressive ramp-up and bottoming resistance was awesome. The kit suspension holds the bike a little higher in the stroke all the time and has more damping force than standard without getting harsh. But I really liked the feel of the fork and that meant it was definitely too soft for Ricky, which he conformed.

On the Mint race bike the setting was stiffer which allowed those guys to ride farther over the front of the bike, use the front brake more and hit bumps harder. It never got initially harsh but for someone my speed it wouldn’t settle in the turns as much as the earlier bike did. Funny thing is, I’d be willing to be I could have a good suspension tuner make the standard X suspension work just as good as the A-kit suspension on the race bike, and I intend to find out. The race bike makes the standard bike (ours) feel wallowly in comparison, which in the real world it is not. getting this feel may be the biggest hurdle.

Truthfully what really stands out and what a regular rider can take away from seeing a bike like this is the attention to detail and prep that goes in. It is years of learning how to prevent problems and DNFs. Protecting vital parts and systems like the JCR Speedshop redundant starter button on both sides of the handlebar. The radiators are protected with wire mesh for extra brush resistance without challenging the cooling system. Hoses are double wrapped. All of the wires are routed carefully and protected anywhere there could be problems. The swingarm is braced and reinforced at the chain guide. A JCR Speedshop Zip-Ty sharkfin protects the rear disc rotor. A P3 carcon skid plate protects the engine and when the riders noticed a little bit of a noise change from the new plate, foam was added to make the bike just right. This is factory level setup and tuning. Addressing a rider’s every need so they don’t have to think or worry about the machinery, just go fast!

Common off-road racing parts like the IMS fuel tank that holds and extra gallon of petrol and has a quick-dump dry-break receiver. The Renthal bars ride on a BRP dampened bar mount with a Scotts steering damper installed. Nitro Mousse inserts keep the Maxxis tires rolling.

So the results speak to the hard work put into the bike. Winning the overall in the Mint 400 was accomplished in a very public test run of the new race bike. It wasn’t easy as Jacob Argubright kept then honest all day on a Kawasaki KX450F and another CRF450X rounded out the podium.

We got a great feel for the potential of the new X as a racer and it will help us find a happy balance in our long-term bike. Knowing were a limit is and keeping a tune so it gets as “factory rideable” while keeping the ease of modifying for the average rider in mind. Soon through JCR Speedshop you will basically be able to get most of the stuff the team is running on the race bike, if not a complete race bike–for a price. And you can follow along aw we do more and more things to our CRF450X as well.

If you want to hear us talk more about this bike, check out our Taco Tuesday Tech Talk in the YouTube video below and you might even get to hear Ricky Brabec answer some questions that may or may not be related to this bike. If you like it, subscribe to our YouTube channel while you are at it.