Front center: The front axle to
crankshaft measurement is called
the “front center,” and the shorter
the front center the more agile the
chassis at turn-in. For 2009, the
CRF450’s front center has been
reduced by 15mm.
A: Think about it for a second. The front wheel is 15mm closer to the engine, while the rear wheel is 18mm farther away. The weight bias has been moved forward and the head angle is steeper. Trail has been increased and the seat height reduced. The overall weight has been lowered and the width at the rider’s knees is narrower. We don’t know about your cognitive powers, but that is a completely different Honda from what we have known since the great 1993 chassis was neutered in the name of stability. We’ll get to how it performs as we move along. Q: HOW NEW IS THE 2009 ENGINE DESIGN? A: Totally new. It shares nothing with the previous design...and we mean nothing! Valve train: Say goodbye to Honda’s innovative forked Unicam valve actuation system. The 2009 Honda uses a conventional four-lobe camshaft and individual rocker arms. Connecting rod: While the stroke remains the same, the connecting rod is 3.5mm shorter ( 105. 6 to 102.1mm). This changes the side force on the cylinder wall, allowing a quicker turnover to the 11,450 rpm rev limiter. The bore-and-stroke is 96mm by 62.1mm. Crankshaft journals: Honda’s engineers relocated the crankshaft main journal cradles (inside the flywheels) to allow the big-end diameter to be reduced from 34mm to 33mm. Additionally, the crankshaft cutaway eliminates piston skirt contact at bottom dead center (BDC). Head: The cylinder head’s combustion chamber is shorter yet has a larger volume squish area for better flame propagation. The overall dimensions of the head are greatly reduced. The camshaft sits lower in the head and the cam sprocket is now press-fit to the camshaft. Valves: Lightweight titanium intake valves and redesigned valve springs reduce overall engine height and permit higher rpm. The intake valve stem diameters have been reduced from 5. 5 to 5.0mm. Exhaust: The exhaust system exits the left side of the head instead of the right side and snakes around the