Plug in: The gray plug is where the ECU programming light
connects. Note the dust seal on the steering stem bearing.
Go: Last year the power was broad, but lacked personality.
This year it is torquier and quite unique.
2013 RM-Z450 the Suzuki has the best roll-on power and super- competitive power from 5000 rpm all the way to 8400 rpm. After 8400 rpm, it loses ground to the YZ-F, SXF and KX-F. No big deal, because the 2013 RM-Z450 is defined by its thrust off idle. Its tractable feel and easy-to-use powerband are its best traits. Is it fast? It is if you use the power properly, but in a flat-out wax race, it is more manageable than monstrous. Is it better than last year’s RM-Z450 engine? Yes, and no. Yes, for a finesse rider, and no for a hard charger. Q: CAN THE RM-Z450 ENGINE BE MADE BETTER WITH SIMPLE MODS? A: Yes. MXA’s three-prong attack was to swap out the stock map coupler for the white one, gear it down by one tooth with a 51-tooth rear sprocket and substitute an aftermarket exhaust system for the stocker. This triple combination makes the RM-Z450 leaner, more aggressive and able to breathe. Q: HOW DOES THE 2013 RM-Z450 HANDLE? A: The RM-Z450 feels like the front end is attached to a roller-coaster track. The yellow bike can dive inside of every bike on the track—unless that bike is another Suzuki. How did Suzuki get their bike to turn so well? We don’t really know. You would expect to find that Suzuki’s frame geometry would be as much as 2 degrees steeper and armed with less trail than the red, green, blue and orange brands, but just the opposite is true. It doesn’t have the steep head angle normally associated with sharp cornering and its trail is actually longer than the other brands. None of these numbers would recommend it as the sharpest-turn- ing bike made, but motocross bikes don’t live or die by a single dimension. The Suzuki RM-Z450’s geometry is a mystery—even to those familiar with the art of geometry. The proof isn’t in a single frame dimension, but in the interplay of every number, from head-angle degrees, to millimeters of trail, to inches of wheelbase, to percentages of weight bias. Somewhere in that magic mix of numbers, Suzuki has combined the turning ingredients in with the correct amounts. Don’t let the math confuse you. Just accept that the Suzuki RM-Z450 is the best-turning motocross bike on the track. On the other hand, it is very jittery at speed and alarmingly skittish in the rough. Q: HOW IS THE SUSPENSION ON THE 2013 RM-Z450? A: We didn’t like the forks in their stock settings. They had a jackhammer feel that worked great on a Supercross track, which is where we first tested the bike, but they were jarring on an outdoor track. The quick fix was to back out the compression damping, fiddle with the spring preload and try to find the perfect fork height to load the front end enough to activate the front forks— but not so much as to corkscrew the front tire into the ground. Fork height is critical on the RM-Z450 because of its quick cornering. If you let the forks drop too much or have the fork legs too high in the triple clamps, the bike will oversteer. In the end every MXA test riders felt that