They call it the Race to the Clouds, and the annual climb up Pikes Peak attracts stock cars, sports cars, trucks and motorcycles.

But it's the big rigs, thundering at upwards of 90 mph, that really set the mountain rattling.

At the 81st running of the Pikes Peak International Hill Climb in late June, veteran stunt and race driver Mike Ryan once again won the big rig division in his 2000 Freightliner Century Class ST. He ran the 12.42-mile gravel course - packed with 156 corners, hairpin turns, and cliffs of 2,000 feet with no guardrails - in 13 minutes, 26.63 seconds. That was just 5.23 seconds slower than his 2002 record-setting time.

Ryan's race Freightliner featured a race version of the Mercedes-Benz 501 V-6 twin turbo that produced up to 1,450 horsepower. He rode on Michelin tires that were low profile duals with special hand-carved tread patterns, to better tailor the tire to the tricky terrain.