By the Testing Staff of TransWorld Motocross

The Honda CRF250R came away as the hands-down winner of our 2005 250cc four-stroke MX shootout, but after a few months in the hands of the TWMX staff, it was time to give Old Faithful a face lift. Having seen Jim’s Cycle Center’s Mike Brown beating full factory bikes aboard his Pro Circuit-tuned privateer Honda, the choice to send our bike to Mitch Payton and his crew was a no-brainer. After five months of twice-weekly riding and a dozen or so weekend races, our trusty CRF was looking and running a little ragged. The motor felt a little tired, the suspension was soft and the bike had lost its showroom luster. After a couple weeks inside the confines of the Pro Circuit race shop in Corona, California, the bike we picked up was almost unrecognizable.


In stock condition, the CRF250R has better low-end throttle response than the ’03 model, but it still lacks the torque of its yellow, green and blue competition. The power comes on strong in the middle and revs out on top decently. In its clapped-out state, however, our test bike had pathetic throttle response, soft mid-range and a noisy top-end overrev.

Pro Circuit tore our motor completely down and installed its proprietary race piston, camshaft, valve springs and clutch springs. The head was modified to race team specs and the motor package was rounded off with a Pro Circuit Ti-4 GP exhaust system and a better-breathing TwinAir air filter.

On the track, we were astounded at the newfound performance that Pro Circuit coaxed out of our test bike. In addition to being freshly rebuilt, the powerplant now boasted a more aggressive powerband with an authoritative bark, right off idle. The low-end power gains were the most noticeable, as the bike is now quite aggressive out of corners, boasting more power than even the beefy Yamaha YZ250F down low. We found that thanks to the added bottom-end power output of the bike, we could ride the bike in a taller gear in many sections of the track. Furthermore, rolling the throttle on without any clutch work was possible, even when exiting the tightest of corners. The mid-range and top-end gains were also quite notable, as the bike had enough added power and overrev to carry each gear a few bike lengths further. It was the low-end improvements, however, that we remain most impressed with, as this is where the stock machine lacks the most. All of our test riders, from beginner to pro, enjoyed the much-improved snap of the Pro Circuit engine. We’ve also found that unlike many modified 250cc four-strokes we’ve tested, the PC CRF remains as easy to start as it was in stock condition. With a dozen of hours logged on the new motor, it still has the same tight, snappy feel it did when we were first reunited with it.


On the track, the suspension on our bike was too soft and spongy for all but our slowest beginner rider. Even when new, the CRF250R is set up for a rider who falls within a target weight range of 145-160 lb., and it is easy to get both ends to bottom with a heavier or faster rider aboard.

Jim “Bones” Bacon is the suspension guru at Pro Circuit, and in the past we’ve found that he has a tendency to valve his stuff on the stiff side. Bones is, after all, used to working with racers who charge hard, so his aggressive settings are quite understandable. That said, we asked him to valve our fork and shock for a rider about 10 lb. lighter than our average test rider, so our less assertive test riders would not have to adapt to aggressively set up suspension. Bones replaced our stock TK fork and TK shock springs with TK and TK units, respectively, then revalved both ends to suit a 165 lb. Intermediate level rider.

To help the CRF corner better, Pro Circuit also installed a set of its 22mm offset triple clamps, which tighten up the front end and are claimed to help the bike corner with more front-end traction. Fit and finish of the bike included a set of PC graphhics by N-Style, a set of beefy Pro Circuit footpegs, a quick-adjust PC clutch perch and of course, a Pro Circuit Launch Control starting device.

On the track, the bike’s manners in all sections of the track were vastly improved. Gone was the spongy feel of the worn-out stock fork and shock, as both ends now have a much more positive, firm feel in both acceleration and braking chop. As delivered, the fork was a bit harsh feeling under braking, but a couple clicks out on the compression adjusters cured that sensation in a jiffy. Jumping is a much more predictable affair, too, as the bike now soaks up jump faces predictably instead of bottoming on more aggressive take-offs. Landing, too, is a more controlled affair, as both ends are nice and progressive through the entire suspension stroke; a nice firm feel at the ends keeps the bottoming sensations to a minimum.

When coupled with properly set-up suspension, the 22mm offset triple clamps work wonders for the cornering mannerisms of the CRF. In instances on the track where the front end used to have a pushing sensation, the bike enjoys abundant levels of front-tire traction, and everyone who rode the bike commented on its nimble cornering abilities. On flat, hard-packed corners or in tricky ruts, a little body English is all it takes to get the CRF to change directions. Thankfully, the bike maintains an acceptable level of high-speed stability, too.


While our bike may not have gotten the full-on treatment that Mike Brown’s National-caliber racer did, we were pumped to find that our well-used test bike could be brought back to life as a lethal race weapon with a realistic monetary investment in the motor. Sure, a little over $2,000 in motor work sounds shocking in comparison to the few hundred that it takes to get a two-stroke running like a striped ape, but this, ladies and gentlemen, is the harsh reality of the era of the four-stroke motocross bike. Better get used to it!


With the addition of Pro Circuit’s 22mm offset triple clamps, our project CRF250R gained some added cornering agility. Throw in the added horsepower and improved suspension characteristics, and we’ve got the most sought-after 250cc four-stroke in the TransWorld Motocross garage! Here we let Alloy’s Jeremy Mallot take the bike for a spin, but as soon as we got the shot, we pulled him off the track and told him to get back to the mall…