The unbearable lightness of biking: new mountain bikes get lighter, smarter.

• Author: Knowles, Skip
• Position: Executive Living

GOOD NEWS--unless you are an orthopedic surgeon: the mountain bike industry is building smarter bikes that cram more performance into a lighter package. Mountain biking is the perfect combination of stress-release and cardio pump, but it can also be dangerous. Equipment plays a big role in avoiding accidents, and the new breed of "smart" mountain bike shocks is providing cross-country bike lightness in a machine that can blast over rocks, roots and ruts like a downhill racer.

Bikes that Think?

The type of steed you need is dictated by riding style. On one extreme, strict cross-country riders planning to log maximum miles on mellow trails will still find the lightest hard-tail bikes (no rear suspension) tough to beat, because weight is everything.

At the other extreme are the downhill chargers wearing full motocross gear, along with the freestyle crowd, for whom heavier bikes with flexible suspensions that provide greater stability and control are mandatory. Moab bike shops have perfected the freestyle bikes, built for tricks and cliff drops. Park City and Salt Lake shops are the place to seek out the overbuilt downhill bikes used to bomb ski runs off-season.

The majority of us fall in the in-betweens, on a general-use cross-country bike, and that is where manufacturers have focused development.

A trick new Stable Platform Valve (SPV) front shock shows the biggest gains, eliminating the old tradeoff that for years dictated that riders who wanted cushy suspension for bombing downhill were penalized by energy-eating mushiness when pedaling uphill--as well as excessive weight. Dan Hall at the high-end Wild Rose bike shop in the Avenues has ridden the SPV system bikes and says the difference in how the SPV-shocked bike puts the pedaling energy straight to the ground is dramatic. The valve is a dampener that resists low-speed impact to fight the loss of pedaling force but opens up and softens to blast over obstacles. Bottom line? "It does the thinking for you, adding very little weight," he says. "Now you can just ride hard, keep your hands on the handlebar and pick a tough line--let the shock do the work." Top shock-makers Manitou, Fox and Rock Shox all use the SPV system or close variations.

What You Pay For

Bikes, like photography equipment, fall strongly in that realm of "you get what you pay for." The threshold of good quality for bicycles is around $1,500, Hall says, and Wild Rose builds bikes with the SPV technology starting at around...