Guest reviewer in the Field Tested column this week: Aaron Gulley, the deputy editor at Outside's Go and a very committed gear head. Aaron finished a really impressive 48th in the grueling Leadville 100 race this year (out of 653 finishers) on Scott's top-of-the-line full-suspension bike, on which he will here hold forth. 

Field Tested: Scott Spark Limited
From: $8,200
Verdict: If you can afford it, don't think twice.

Bike racers love to say, it’s not the bike that matters, it’s the engine. And while I generally subscribe to this noble truism—as in, stop your whining and go train harder!!—on Saturday, while I was racing the Leadville 100, it occurred to me: If the bike doesn’t matter, why were all the fastest guys humming along on high-end cross-country racers that cost as much as a new car?

For this year’s LT100, my second consecutive attempt, I traded out the 5.5-inch, 26.5-pound all-mountain ride that I raced last year for a top-of-the-line Scott Spark Limited, which the company graciously lent me for testing this spring and summer. I’ll get slightly ahead of myself to say that, by the time I splashed through the course’s last mud puddle, I had trimmed 51 minutes off my 2007 time and had an immeasurably more enjoyable race. Sure, there were lots of factors: the cool weather, the overnight rain that lead to perfectly tacky conditions on the course, a different training regimen, and successful nutrition (as in, no barfing up my food this year!). But I also firmly believe that my relative success came in no small measure thanks to the Scott. This bike is, quite simply, one of the most stunning pieces of technological innovation on the mountain bike market today.

For a course like this, which climbs some 14,000 feet on predominantly dirt roads at elevations between 10,000 and 12,600 feet, you want to ride something light. (Extra heft amplifies the effects of the thin air.) I weighed my Scott Spark Limited at a head-slapping 21.19 pounds, with pedals. To put that in perspective, in the weeks leading up to the race, the cycling media reported with some incredulousness that Dave Wiens and Lance Armstrong—who, by the way, went on to finish first and second respectively—would both be riding sub-23-pound bikes. When I read that, I had to weigh the Scott again. Yep, still 21 pounds!

The real story of the Spark, however, is what you get for that nominal weight. I imagine numerous racers were riding bikes lighter than this, but those were either stripped-down hardtails or bare-bones single speeds. The Spark is a four-inch (front and rear) carbon race bike with at-your-fingers controls for the fork lockout and three-stage shock. Put another way: This frame is so light (3.4 pounds) that Scott had plenty of latitude to add extras like bar-mounted controls. The frame is extremely rigid for its featherweight, but the single-pivot suspension still swallows up the rough descents. Kudos to DTSwiss: The carbon XRC 100 fork is incredibly light (and sexy looking!) but plenty stiff for my 155-pound frame; and the Scott Nude TC shock (which the Swiss company builds) allows you to switch from fully open (for descents) to traction mode (medium stiffness for improved climbing) to fully rigid (for zero power loss on pavement). The wheels—comprised of the new DTSwiss 190 Ceramic SL hubs mated to Ritchey WCS rims—felt snappy and light going up (I believe these weigh an ungodly light 1250 grams for the set; and you can feel it!), without compromising any durability or tracking going down. Two other wicked features: 1) The integrated carbon seat post shaves some weight and looks damn cool; and 2) the integrated carbon bar/stem combo is one of the wildest developments I’ve seen (though it makes it tougher to get the right size; incidentally, this bike fit me perfectly). Oh, and I love Magura Marta brakes; the action is crisp, and the large, 180mm rotor up front provides incredible control.

On the course, I loved the lockouts, as I could instantly transform my full-suspension ride into a veritable road bike, making it much easier to pull along with a paceline on the hard-pack rollers. Not to put to fine a point on it, but having all of these controls on the bars is such an advantage. Dozens of times, I saw other riders reaching down on their frames to flip their ProPedal switch or turn off their shock lockout, and more than once they ended up either slowing down to do it or nearly crashing in the process. Going uphill, which we did a lot, I found myself passing other riders frequently. The traction mode on the shock really helps the bike’s rear end grip the trail, and I could feel how light those wheels really are. But unlike many guys on hardtails, who had to pick their way down some of the trickier spots, I could throw the full-suspension down the rockiest hills, thereby preserving my hard-fought placements on the descents.

Speaking of fast descents, one of the figurative high points of the race came about two miles from the summit of the Columbine turnaround, when Dave and Lance zoomed by me (already 30 minutes ahead of me). Man, were those guys moving! And contrary to what he said before the race, based on the intent scowl on his face, Lance was definitely “in it to win it.” That makes Dave’s success even more impressive. This was his sixth consecutive win at Leadville, but riding Lance off the wheel has to rate as a career highlight. In fairness, it’s also clear that Dave probably wouldn’t have finished quite as fast—he shattered his old course record by 13 minutes, finishing in 6:45:05—without Lance to help him push that pace. (Lance finished two minutes after Dave.)

As for me, I finished in a sprint against my training partner, who caught me in the final mile (and pipped me at the line!), to take 48th place in eight hours and 16 minutes. It was about what I had expected, though I had hoped to be a touch quicker. Knowing that I was riding the ultimate bike for this course, I have nothing to blame except my legs and my tenacity. So for Leadville 2009, I guess I’ll have to work harder on that engine.
—AARON GULLEY