Tire pressure makes an enormous difference to mountain biking. If you're riding over rough terrain or soft surfaces like sand, lower pressure provides a little more stability and traction. On the road, you want higher pressure because it means that less of the tire’s surface area will come into contact, thus allowing for greater speed. What most riders tend to do is set their bike up for one type of terrain and suffer through the rest. The ADAPTRAC system has the potential to change that with some patent pending hubs, a dual control valve and a CO2 power pack/regulator. The system allows the rider to raise or lower tire pressure on the fly by using a pair of handlebar-mounted toggles. Tire pressures are displayed through analog gauges, also mounted on the handlebars. ADAPTRAC uses 12x142mm rear and 15mm front axles. Wheels are removed as normal. The system works with readily-available 4- to 20-ounce CO2 tanks. As of yet, there's no word on price, but given the cost of most types of cutting-edge bicycle technology, you can expect it to be expensive. Is it worth it? That depends on how often and how far you ride.