Twenty-four hours of ride time on a 250cc four-stroke dirt bike may not seem like much. In the big picture, that’s just two one-hour sessions a month for a year, or two weekends a month for an hour each time. At that pace, you’d have plenty of time to perform proper maintenance and ensure everything stays within factory specs. But what if you ride a 250cc four-stroke for 24 hours straight in race mode, with no major maintenance, oil changes or valve adjustments? How would it hold up? Would it be wrecked afterward? We know 24 hours straight is nothing for the big-bore four-strokes; they do it all the time. To test our theory, we grabbed our long-term 2025 Honda CRF250RX test bike and competed in last October’s 3Bros 24-Hours Endurance Race at Glen Helen Raceway.
Photography by Trevor Hunter & Nitzen
Our CRF250RX had already seen some use, including regular testing and competing in the 3Bros 6-Hours Endurance race at Glen Helen back in March one year ago. For the 6-Hours, we rode the CRF250RX and found that a smaller-displacement bike, compared to a larger one like a 450cc four-stroke which endurance racers usually prefer, offers certain advantages. It’s lighter, easier to maneuver, and requires less effort to ride, which we considered major benefits over heavier, more powerful bikes for endurance racing. We liked the CRF250RX in the 6-Hours but wanted to give it a more challenging endurance test, a 24-hour race.
Around the Clock Prep
Heading into the Glen Helen 24-hour race, our CRF250RX was still in great shape. It had been well maintained, but it needed some modifications to be ridden comfortably for 24 hours straight in race mode. Our goal was to keep it as close as possible to stock and just get it to the finish line (okay, and maybe on the podium, too).
The first thing that always comes to mind in a 24-hour race is lighting, which will be your most expensive can’t-do-without modification for an around-the-clock race. After all, half the race is at night, and, of course, there is no stadium lighting to light up the track. This means you must make your own light if your bike didn’t come from the factory with one, like our RX. Here is where Baja Designs came to our rescue.
We installed their Honda Squadron Pro/S2 Sport LED Headlight combo kit ($412.95), originally designed for Honda’s CRF450L/RL dual sports. For our bike, the four-bulb Squadron Pro was powered by the bike’s electrical system, but you’ll need to purchase Source OffRoad’s CRF Plug-and-Play Wire Harness ($76.95) to complete the connection. We used the two-bulb S2 Sport part of the kit as a backup light, running it off an auxiliary battery system we rigged ourselves and mounted on the handlebars. Hardwiring both lights to the bike’s power system would put too much strain on the RX’s battery, which will eventually get sucked dry of power. Overall, installation isn’t too bad, maybe a couple of hours in the garage. With the Squadron Pro LED lighting kit installed, we now had approximately 4095 lumens worth of illumination, which is plenty. The S2 Sport is rated at another 1581 lumens.
For that factory-installation look, we borrowed a Honda CRF450L dual sport front fender and headlight visor and bolted everything into place. You must also swap the RX’s front brake cable for a CRF450X because it can catch on the L’s headlight shroud. We kept our headlight safely packed away during the day. We didn’t want to risk damaging it, so we just plugged it in after the sun set.
Helmet lights completed our lighting system, and we highly recommend using them. With all the lighting complete, you can now sign up for a 24-hour race.
We made a few more strategic modifications that we feel are very important, but not necessarily required, for endurance racing.
We didn’t want to deal with flats, so we installed Dunlop mousse foam inserts ($145-$200) inside our Dunlop AT82 tires ($125-$135). If you’re fortunate, you might know someone (luckily, we do, Honda) with an RX who will let you borrow their wheels, so you have a spare set for quick changes, repairs or strategies—very nice to have but, again, not essential. Since the AT82s are bi-directional, our first set of wheels had the scoop knobbies facing forward for sandy conditions, as the track was at its deepest early in the race. Our second set was flipped to the hard pack setting since the track would dry out as the race progressed.
We stuck with the RX’s original 2.1-gallon fuel tank and hand-twist gas cap. A dry-break dump-fill system would have been nice, but our reliable, much cheaper 2.5-gallon Tuff Jug utility can with its Ripper Cap worked just fine, albeit a little more slowly. If you’re all about saving seconds, a full dry-break system is the way to go, but a good one can cost more than $1000. We’re just fine with our $63.44 Tuff Jug/Ripper Cap system.
The stock Honda grips are notoriously tough, and we wrecked our hands on them during the previous 6-Hours race. We learned our lesson and installed ODI’s new Nomad Lock-On grips ($35.99) for the 24-Hours. These grips are very durable and feature D3O technology for extra damping and vibration absorption to keep your hands happy during long races. But even the best grips don’t always prevent blisters in a grueling 24-hour race like Glen Helen’s, as you’ll see in our attached video.
We also added a Corner Coach seat bump ($39.99) to the stock seat, which is easily adjustable for our five riders and perfect for Glen Helen’s hilly terrain. We applied some Stompgrip 3D grip tape ($34.99) to the frame rails and side panels for extra grip. That was about it.
Of course, we wanted to look good out there on the track. Decal Works made our bike look good, and Klim made our riders look good, providing our team with their XC Lite gearset. USWE dialed us in for on-the-bike hydration.
24-Hours Later
Our CRF250RX performed flawlessly for 24 straight hours. Our team logged approximately 315 miles on the Honda that carried us to a podium finish in our class, and all we did was keep the air filter clean, lubricate the chain whenever we could, and make several suspension adjustments to accommodate the ever-changing track conditions. Nothing broke, the lights did their job, and the bike felt almost as fresh on the last lap as it did on the first. We were impressed. Especially considering that our bike had already seen some good use before the race.
After the 24-Hours at Glen Helen, we sadly had to return the bike that had served us so well to its home at Honda, where their technicians quickly got to work refreshing it for other future projects and rides. We wanted to know what they did to freshen up our bike, just like any owner would after a 24-hour race, and they told us, “Not much, really. Just the basics.” They replaced the clutch plates, brake pads, chain, and tires, and performed an oil change and a valve adjustment. And it has been ridden several times since then. As of this writing, the 24-Hour bike we rode, now in other people’s hands, is, according to our friends at Honda, still going strong with 68 hours on its meter.
So, 24 hours of ride time on a 250cc four-stroke dirt bike isn’t really that much after all, even if you do it all at once. The CRF250RX can take it. As for our test riders, though, 24 hours was more than enough, and they needed to freshen-up more than the Honda did.
Be sure to check out our accompanying video, showcasing our experience at the 2025 24-Hours of Glen Helen, as part of our Superhard video series. Enjoy CN
VIDEO | Racing The 24 Hours of Glen Helen – SUPERHARD!
Click here to read the 2025 Honda CRF250RX 24-Hour Review in the Cycle News Digital Edition Magazine.
