The stock CRF450R has been accused of being a little sleepy. This one is wide awake.

Meet Goliath. This is a big-bore Honda CRF450R. It has a 3mm-larger piston in a Cylinder Works top end that brings it to 478cc. We like to call it a Honda 480 because we remember the old days when that was the bike to have. Kids, look it up.
Goliath might not sound that big, but it is. In these days of highly efficient motocross motors, providing a little extra displacement is like setting an engine free. We actually agree with the school of thought that says most riders can’t use the power that a stock 450 produces today, but that’s not the whole story. It doesn’t mean that we can’t enjoy a good, arm-stretching power overdose once in a while. The CRF480 satisfies our darkest, Neanderthal cravings.
This bike was built for a real-world rider who just wants to have fun on weekends, but he didn’t have a death wish. The big-bore kit was just one item in a long list of modifications, and not all of them were aimed at more power. Some helped tame the beast. The engine got a Vortex ignition so we could quickly and easily try different engine specs. It also got a Hot Cams Stage 2 camshaft and a beautiful FMF Factory 4.1 titanium/carbon fiber pipe with a Megabomb head pipe. The chassis got an oversized front brake and Factory Connection suspension. It wasn’t an especially cheap project, but it wasn’t as expensive as you might think. All of the parts were obtained from Rocky Mountain ATV/MC at deep discounts. The cylinder kit, for example, cost $539.99, whereas full retail is $659.99. Same goes for the camshaft: $215.99 versus $269.95. Some of the parts were Rocky Mountain’s in-house brand, Tusk. An entire wheelset was $550. Most other brands are well over $1000.
For the suspension, it’s hard to quote a universal price. It can vary according to the service required. Factory Connection was the choice here simply because we’ve come to trust them with virtually anything.

The Cylinder Works big bore kits makes the Honda into a 478.
The Cylinder Works big bore kits makes the Honda into a 478.

When all the work was done, it was like the Honda went to sleep in a field of alien pea pods. It woke up with a complete personality transplant. You know how the stock CRF450R gets trash-talked for being a little mild and sleepy? People say it’s one of those bikes that gives you what you need and not necessarily what you want. That’s not the case here. The CRF480 is a mauler. From down around 3000 rpm to 5000 is the biggest difference; the bike’s torque is increased dramatically. From 5000 rpm to 8000, the motor gets nasty and downright hard to hang on to. Above 8000, we don’t really know what happens. We needed a break by then. With most big bores you lose rpm on top and sometimes even peak power. The Hot Cams’ cam and FMF Factory 4.1 dualies effectively counteracted that limitation, so the Honda gained everywhere. It still seems to taper off on top, but that isn’t because it lost anything; it’s because it gained so much down low.
We’ve ridden a lot of fast motocross bikes. In most cases, you can hide from the power increase when you get tired. You simply keep it in the lower part of the powerband where it’s easier to ride. In this case, that’s where the biggest power increase is, so there’s no hiding. The CRF480 requires an adjustment to your riding style. When you’re fresh and strong, meet it head-on. Ride it in the middle of the powerband and hang on. You can ride most tracks in one gear, revving it out in the straights and doing a little light clutch work in the turns. If you’re on top of your game, good for you. If you’re not the perfect athletic specimen, you have to toss out a lot of the riding technique that usually works. First of all, don’t twist the throttle. Keep the revs really low and steady, adjusting your speed with the gearbox. You still can spend a lot of your time in one gear, but it would be a very tall gear.

Visual and audio artwork.
Visual and audio artwork.

We never stalled the big Honda. That’s surprising, because we were daring that to happen by running such tall gears. The Vortex ignition is mapped extremely well. It never pops, coughs, backfires or dies. The Honda’s manners aren’t as flawless when it’s cold, though. It’s tough to start in the morning. It can take a half-dozen kicks—big, strong, expensive kicks. We don’t think this is entirely the fault of the big-bore kit, because it starts so easily when it’s warm. A mapping solution is probably possible given enough time. The Vortex is the most adjustable ignition made. You can install 10 different maps and even toggle between any two of them with a handlebar switch. We will point a finger at the big-bore kit for an increase in vibration.
Factory Connection did a spectacular job with the suspension. It isn’t easy to make a bike with this much power so easy to handle. The softer rear spring allows you more adjustability through shock valving. You can make the bike super cushy and comfortable or dial it up for fast riders on rough tracks. We set this bike up for a 180-pound vet intermediate. Faster and heavier riders will probably like the stock spring better. The air fork was cushy, smooth and, of course, adjustable to a fault.
Who wants this kind of horsepower? As it turns out, everyone. If you want more out of the 2014 or 2015 Honda CRF450R, you’re in the majority. You can tackle the issue with a cam, compression, head porting and a pipe, but you’ll actually spend more and very likely get less. Displacement boosts are still the most cost-effective hop-up. Plus, all these modifications are bolt-on parts. You don’t have to send away your head, wait around and hope for the best. If you ever want to return to stock, it can be done fairly easily.
This particular bike is privately owned and will probably be taken out of our greedy little hands very quickly. We still want to experiment with it as a desert racer, an off-road bike or even try to conquer some of our most fearsome hills. There’s still time, though. It’s going to be a busy weekend.

To read the test of the stock 2015 Honda CRF450R, click here.

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