At last year's Dirt Rider 24-Hour, the L.A. Sleeve CRF430X was a little more-actually, an excessive amount more-than what we'd expected. Let down by too much? Maybe so. L.A. Sleeve shrunk the bore just a bit more for DR, and we took another spin on its 24-Hour Torture Test bike. Wouldn't you know it-the bike was less powerful and easier to ride. Bingo, the company got it. Now the snap of the 450, specifically the more-abrupt snap of its previous 430, was diminished to a very smooth and linear build that actually gave the 400 a lighter and more maneuverable feel in tight going. On faster roads and open washes, it is off in terms of speed, but riders were able to get on the throttle sooner and hold it wide-open longer. It has plenty of poop to lift the front end yet will torque down to a low, low rpm and still pull out of it. Now wheelspin and sudden acceleration happen only when you want them to. This is the type of kit for those looking for something more than what a big-bore 250F can offer, without any of the durability issues that can arise from hot-rodding a small-bore motor, and the cost is a lot less shocking, too. The kit, including the labor to install the sleeve. is right at $480.
To see the full list of parts on this bike, check out www.dirtrider.com.