125 XC-W (MY2017)

KTM built this one around a single job: getting up something steep and nasty without wearing the rider out. The 125 cc liquid-cooled two-stroke single is quoted at 37 hp and 16 lb-ft through a six-speed box. The chassis is a 25CrMo4 steel double cradle with WP XPLOR suspension, adjustable at both ends from the factory. Ground clearance is 14.6 in (370 mm), with 11.8 in (300 mm) of travel up front and 12.2 in (310 mm) at the rear.

This is a specialist, and it does not pretend otherwise. It rewards a rider who already knows how to read terrain and wants a machine light enough to be muscled, hopped and dragged through sections where bigger bikes simply stop. It ages well because there is little on it to go wrong and plenty of support behind it. The honest caveats are the ones you can measure: a 37.8 in (960 mm) seat that suits taller riders, a 2.5 gal (9.5 L) tank that keeps loops short, and a Mikuni TMX carburetor that wants proper jetting before it behaves.