McMahon Racing Cycles´ 325R project bike is a titaniüm tour de force. The 3A1/2.5V alloy Frame, built to Steve McMahon´s design and neatly welded by Sandvik Special Metals in Kennewick, Washington, came hung with an impressive collection of MRC–made titanium parts, including the stem, handlebar, seatpost, cartridge–bearing bottom bracket, pedal,axles, and even the springs in the ultra–powerful Power Link brakes.
  Up front, McMahon´s 1.6–pound fork uses straight, 1–inch–diameter titanium blades bonded into a welded chrome–moly unicrown and steerer. This provides the best of both materials: the lightness and smooth ride of the titanium legs with the required rigidity of the steel steerer and unicrown (onto which the brake bosses are attached). Rounding out the collection of titanium are the spokes and ubiquitous Flite saddle.
  Despite it all, our 325R weighed a relatively hefty 21.45 pounds, the most of any bike in this test. Its 3.85–pound frame (5.45 with fork) earned similar honors. This is partly because the frameset is no one–off project but a production model selectively lightened with a few mildly exotic parts. You can buy this bike, which reflects McMahon´s philosophy that bicycles are made to be ridden—and ridden hard—not drooled over while suspended from a meat scale.
  In keeping with his intent, I did just that, hammering the 325R for more than 200 miles on premier singletrack during Fat Tire Bike Week in Crested Butte. By the end, I´d coined a new phrase, "hammered dogmeat," to describe my wasted state, but the bike held up fine, save, for a smooshed rear derailleur cable stop when I toppled over while negotiating a steep rockfall. If there were any scratches they went unnoticed on the frame´s attractive, bead–blasted matte finish.
  Through it all, the bike´s handling, fit, and control were perfect. I´m convinced it made me a better rider. On the jarring descent from Teocalli Ridge, the 325R soaked up the fresh–cut singletrack´s bumps almost as well as a suspension bike. Its fat, 1.5–inch down tube and solid–feeling fork gave me the confidence to clean a couple gnarly boulder fields on Trail 409´s technically demanding reroute. Steering response was very light, making it ideal for bombing precisely between the trees of the Snodgrass Trail´s cool aspen grove. Yet on the warp–speed dirt road descent from Schofield Pass, the bike practically steered itself. Finally, the titanium´s magical smoothness helped retain my good humor on the grueling Doubletop and Deer Creek trails, even after long hours in the saddle.
  McMahon´s Power Link brakes were particularly impressive. They´re right up there with the WTB Speedmaster and IRD Rotary for stopping power and modulation, and fit the same U–brake–type mounting studs. Like a rollercam, the Power Link arms are forced apart by leverage from a center–pull cable, rather than together by a straddle. But instead of a cam or rollers, the pivot is a pair of straight alloy beams that disconnect easily to clear fat tires, even with ultra–narrow rims.
  While the brakes offered ample tire clearance, the Power Plate booster straps were closer to the tread and clogged solid with an adobe–like mix of black mud and green skunk cabbage on rain–sodden Trail 403. Fortunately, the 325R´s tubes won´t rust, because I had to rinse it several timen in roaring, snow–fed streams to keep the wheels turning. When I decided to remove the Power Plate straps it was just in time for a run of fair, dry weather. For the record, the brakes still worked very well, though the straps make them better.
  The only problem I had with the 325R came closer to home on the bike´s maiden voyage, when the retaining sleeve on the cartridge–bearing bottom bracket separated from the titanium axle. This let the crank migrate toward the chainstay, until the granny ring started sawing into the tube. McMahon sent a better–glued replacement axle the next day, which held up for the remainder of the test. It´s academic, though, because he says he plans to switch to a threaded bottom bracket shell — with an MRC titanium axle, of course.