One of only three ever made, this Brown Brothers Racing “YZ426S” is a truly fascinating hybrid motocrosser. Marrying the lightweight aluminum-frame from the (early-2000’s) nimble Honda CR250R with the Yamaha YZ426F’s proven power plant to deliver this high-performance made-to-order dirt-goer that sold for $20k back in the early 2000’s. Combining the best of both worlds, it’s not hard to see how this rare hybrid was chosen to be featured on the cover of Bike Dirt Magazine in December of 2000.
As you can imagine fitting a 426cc four-stroke powerplant (of a different manufacturer) into a frame that was engineered to house a 250 two-stroke is no easy task. Starting with two brand-spankin’-new bikes (a 2001 Honda CR250R & a Yamaha YZ426F) the Brown Brothers (the BB of BBR) spend over 100 man-hours toiling over the transformation of this exclusive off-roader before fitting it out with some of the most trick components on the market, at least at the time. Even with the CR’s engine and YZ’s frame being sold to scrapyards to partially offset the overhead costs, the aforementioned creation of these machines should start to give you an idea of how an MXer ends up costing $20k.
The result of the brothers’ efforts is an exceptional machine weighing only 226lbs. By altering the Honda’s frame they manage to make the four-stroke engine fit, exclusively using 7005-aluminum (the lightest available and extremely scarce) should give you a sense of the great attention to detail placed on every aspect of the build. By the time the new frame is complete the entire bottom has been replaced, as has the downtube, and it’s almost unrecognizable as it’s basically a new frame at this point.
Because these are exclusive made-to-order motorcycles, BBR allows their customers to make countless selections in the creation of their high-performance two-wheeler. Bolt composition, handlebar bend and seat-cover are just a few of the options along with a color-choice for the grips hand guards and plastics. The bike is then dialed in for its buyer via tuning the suspension, this includes the suspender’s valving. From there even the standard parts on BBR machines get the royal treatment, being outfitted with with polished and anodized parts and boasting various billet components. Every inch of these bikes are scrutinized over which is readily visible in their final product.
As of present BBR online makes aftermarket parts and high-end $5,000 pitbikes, a feat that actually put them on the map originally in the late 1990’s. So while the Brown bros are still doing their thing, they no longer produce this special hybrid machines making this example about as rare as it gets. According to the seller, of the three made, one was stolen and the other in a museum making this the only BBR hybrid being ridden today, albeit I could not independently confirm this.
BBR is by no means the only company or builders to be making hybrid machines out of an existing chassis and engine, but the brothers’ bikes are reported to handle extraordinarily well while still feeling like an factory-OEM unit. It’s said this thing really shines when it takes flight, reportedly being exceptionally easy to make corrections to while mid-air. Even over a decade and a half later and these bikes are considered by many to be unrivaled. You can find this ultra-rare off-road example for sale here on Craigslist in Redding, California with a price of $18,000.