When was the last time you rode a 125? If it was this century, good on ya'. If it was in the 1970s, it's time you re-learned what you thought you knew...
Yes, air-cooled, piston-port two-strokes like the Hodaka you rode when you were a kid were pipey beasts that alternately bogged and wheelied, fouling plugs and seizing with semi-regularity. Their spindly steel-tube frames and swingarms flexed like a flagpole in a gale, making for handling that was ... let's just say less than precise. Drum brakes didn't. The main thing these old bikes had going for them was their light weight.
Thirty-odd years later (uh-huh), 125cc two-strokes have gained 20 pounds (who hasn't?), but they're also liquid-cooled, crankcase reed valve-inducted and equipped with torque-boosting exhaust power valves. Those engines are housed in rigid (meaning stiff) aluminum perimeter frames that wouldn't look out of place on a superbike. Brakes are now discs, suspension is fully adjustable and travel has grown to more than 12 inches-roughly three times what your old Wombat had.
In other words, they're thoroughly modern motorcycles.
Conventional wisdom holds that two-strokes are dead, today's emissions standards dooming yesterday's technology. But a few European manufacturers-notably KTM and Husqvarna-are continuing to produce and even refine their "ring-dings." Of the Japanese, however, only Yamaha still offers full-sized two-stroke motocrossers-ironic considering it was the tuning-fork company that ushered in the Four-Stroke Revolution with its 1997 YZ400F!
Yamaha is the last of the Japanese manufacturers to offer full-sized two-stroke motocrosse
Hop aboard a 2010 YZ125 and the first thing you discover is it kicks so easy, you could start it with your hand. Pull in the clutch, click it into gear, wind up the throttle and ... whirrr ... um, that's not near enough. Kick it again, wind it out some more this time, slip the clutch and ... brrraaappp ... that's the ticket! This latest YZ makes infinitely more torque than its ancestors, but like every 125 ever wants you to wind it out before upshifting and to bang two downshifts minimum entering corners.
Talk about lightweight: At 195 lbs., the YZ is only heavy compared to a vintage bike. And it makes so much more power that it's power-to-weight ratio is off the chart. Unless you outweigh the bike, the suspension is amazing, letting you jump as far as your pinned throttle hand will let you with nary a care about landing. The brakes are just as good, but you'll seldom use them, so who cares?
Of course, all this pinning and shifting requires a lot of energy, thus you might think 125s are better left to the younger generation. Not a chance: Because it is so lightweight, it doesn't wear you out near as fast as a bigger, heavier four-stroke. Ignore the snickers as you line up at the gate, make peace with the fact that you'll never get the holeshot, and revel in being the underdog as you flow past one lumbering "diesel" after another. If it doesn't happen in the first few laps, relax; it will happen later. Let the 450s dig trenches down on the bottom and run 'er in there high, wide and handsome. Then smack the berm, pin it, fan the clutch and wheelie right over the ruts. You'll blow by them so fast, they'll think they got buzzed by a mosquito.
You might even feel young again.