Timbersled does for dirt bikes what Track N Go does for trucks. Except I think Timbersled's intent is less to enable safe passage, work, and rescue operations during inclement weather than to enable sick motocross races and Darwin Award-approved shenanigans in the snow. Their Mountain Horse conversion kits come in Short Track (ST), Long Track (LT), and Snow Cross (SX), models and arrive fully assembled for simple (probably a relative term) installation on dirt bikes powered as low as 250cc.
Bike brands approved for the Mountain Horse snow-pimping of rides include Yamaha, Honda, Kawasaki, Suzuki, KTM, Husaberg, and Husqvama.
Timbersled's standard and most popular Mountain Horse issue is the ST conversion kit. It includes a 120" long x 12-1/2" wide track with 2" tall paddles. Of the 3 models, the Short Track kit delivers the best maneuverability and control for dirt biking in the mountains with Sasquatch. Its power-to-traction ratio has been designed to accommodate bikes as small as 250cc, though Timbersled designates 450cc motocross bikes as the best choice for ST kit application.
The Long Track kit maintains all ST characteristics, less the 17" it adds in length for a 137" track. The extension provides 20" more traction for use in deep snow, and feels more secure barreling along steep side hills. Its downside: an approximately 8 mph reduction in attainable top speeds. Long Tracks should be paired with bikes 500cc or larger.
SX conversion kits are made specifically for snow cross racing, hard packed snow, and rough terrain riding. They contain a stiffer, 121" long x 10-1/2" wide Snow Hawk track whose center paddles are 2-1/4" tall in the middle, but contour down to 1" at the outer edges so the track appears rounded like a tire. This benefits bikes surging along packed snow on trails and tracks. SX kits are dual suspended, with the same track suspension as the ST and LT models, plus an additional shock in the sub frame/swing arm, for a total of 20" of rear suspension travel.
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