BH G4 Red - Road Bike Action

The G4 blends nearly 100 years of BH heritage with on-the-edge nanotube-carbon-fiber construction techniques and groundbreaking components. To add substance to this description, our 55.5-centimeter, medium-sized G4 weighs 13.7 pounds (6.227 kilos) and its frame slips in at under 900 grams (painted, with an uncut integrated seat mast). Just in case you are thinking that the G4 is another featherweight dandy that couldn’t survive in the real world of professional racing, BH backs its ultra-lightweight racing platform with a lifetime warranty-and has earned the respect of Ag2r, the fourth-seeded team on the ProTour.

THE FRAME

The G4’s relaxed seat angle allows for a roomy top tube, while keeping the wheelbase short.

BH is credited with developing the extended seat tube frame design years earlier for its 2004 Liberty Seguros team bikes, which became the first Global Concept Series frameset. The ‘G’ in the G4 stands for ‘Global Concept’ and is the fourth incarnation of BH’s most elite racer. It is not, however, an evolutionary step. With the exception of its integral seat mast, the G4 represents a fresh, ground-up redesign-beginning with an expensive, high-modulus carbon material, which is impregnated with microscopic carbon nanotube particles. The crystaline-shaped nanotubes replace spaces between the carbon fibers that would normally be filled with lower-strength resin, which creates a decidedly stronger part. THE NUMBERSTo retain BH’s legendary status among climbing specialists, the G4 sports a slackened 72-degree seat tube angle and each frame tube is profiled to maximize stiffness. There are ridges on the center axis of the seat and chainstays, and subtle profile changes along the length of the top tube. The downtube uses a deep channel in its underside to route the control cables away from sight. The channel sidesteps the weight and complexity of internal cable routing, boosts the frame’s strength, and saves 150 grams. BH’s 330-gram straight-blade fork is also profiled to further optimize the lateral rigidity, while its internal carbon lay-up is engineered to maintain a relatively smooth ride. Presently G4s are available in 52, 54, 55.5, 57 and 58.7-centimeter sizes. BH quotes the level top tube length as the frame size to avoid the bike-size fiasco brought on by sloping top tube designs. The 54-centimeter frame weighs 880 grams with a full-length seat mast and paint. Color schemes are blue-on-white and white-on-red.

THE PARTSBH sells the G4 in Shimano Dura-Ace and Ultegra SL versions, and for $7395, you can get one like ours, with a SRAM Red ensemble. The ‘G4 Red’ is the lightest of the three and arguably the raciest-looking, with its charcoal-and-red drivetrain and tubular-carbon-spoked Mavic R-SYS wheels.

BH adds an external rib to the fork blade profile for lateral stiffness.

SRAM’s gearing is made for the mountains with a compact-sized 50×34 crankset, driving an 11×26 cassette. BH riders probably won’t need to cut the seat mast to arrive at a perfect ride height, because there is an internal post that provides 90 millimeters of adjustment. The stubby carbon post is convenient and unobtrusive, and a longer post is available for tall men who ride smaller-sized frames. FSA fills out the front of the cockpit with a comfortable SLK Carbon handlebar and net-forged OS 99 aluminum stem. FSA’s bar blends perfectly with SRAM’s DoubleTap combination levers, which set a new standard for mechanical ergonomics. The G4 Red needs nothing except a willing rider to turn leg power into blistering speed.

THE RIDEThe G4 is a make-something happen bicycle from the first turn of the cranks. Although its top tube is generously long, the relaxed seat angle and short, 40-centimeter chainstays squeeze the wheelbase to a compact 97.3 centimeters. This makes the G4 react instantly to rider input. It will weave through the peloton like a lion in a herd of gazelles, but its quickness is moderated by a 73-degree head angle and spot-on steering geometry. The result is razor-sharp steering, with enough handling left in the bank to blaze downhills.

As one may expect, climbing and acceleration aboard the BH Red is efficient and decisive. It gets moving in a heartbeat and will settle into a steady rhythm for extended climbs or when the time is right for a solo breakaway. The featherweight feeling BH holds true to its promise of lateral stiffness and effective power transfer-but it comes at a slight penalty when the pavement gets rough. Mavic’s R-SYS wheels are unforgiving over the cobbles, as the tubular carbon spokes can actually withstand compression loads, and they deliver the feel of the road to the rider with great clarity.

THE VERDICTDedicated racers, aggressive climbers or anyone who drives the pace of a Saturday ride will fall in love with the G4 Red. This isn’t a machine, it’s a nano-carbon animal, coiled like a spring, ready when you are-to pounce on a sleeping peloton, to demolish a breakaway group, or simply to bust out three hours in the mountains as if you were possessed by the ghost of every Basque who carved his name on the pro cycling tour.

Price: $7,395Weight: 13.7 poundsContact: www.bhbikes-us.com