Debuting with a 3rd place at Paris-Roubaix under Alessandro Ballan, the granfondo GF01 is designed not to be below the company’s race machines, but rather parallel but for riders that may not require or want the performance of BMC’s full on race bike. In doing their research BMC identified the type of rider that could benefit from the GF01. BMC sees the GF01 rider as ambitious, but one that is not necessarily a racer, looking for a bike to tackle long rides comfortably.
BMC outfits the GF01 with endurance geometry that features long chain stays, a slack head tube angle and increased fork rake. The GF01 tips the scale at 995 grams, just 95 grams more than their race ready SLR01. The GF01 is also torsionally stiffer yet 40-percent more vertically compliant. BMC accomplished this by engineering the frame in two sections. BMC terms the down tube, BB86 press fit bottom bracket and chain stays as the base frame and has engineered it for maximum torsional stiffness. The top tube, seat tube and seat stays are then engineered to provide the vertical compliance.
The GF01 is available in six sizes 48, 51, 54, 56, 58 and 61cm. Geometry is based on reach and stack. The frame is outfitted with a 72-degree head tube angle mated to a 73.5 seat tube angle in the 56cm we rode. The 17.6mm tall head tube is connected to the seat tube via a 55.6cm effective top tube. The seat post is thin with the sloping top tube frame design allowing for increased compliance. The seat post is available in three set back options – 30, 18 and 3mm. Knowing that the GF01 will be ridden on rough roads BMC includes an integrated chain catcher.
With a retail price of $6600 one expects the BMC GF01 to be well equipped, and BMC delivers. BMC equips the GF01 with a complete Ultegra Di2 group, Easton EA70 handlebar and stem, fi’zi:k Aliante saddle and Easton EA90 RT wheels wrapped in the wide 28C Continental Grand Prix 4 tires.
On the SLR01 BMC relies on their Tuned Compliance Concept (TCC) technology to give the frame a degree of vertical compliance. TCC utilizes a combination of different grades of carbon, layup, and by applying stepped tube profiles, provide increased vertical compliance while maintaining lateral and torsional stiffness. TCC is used on the seat stays, fork and seat post. The GF01 takes TCC technology a step further with Angle Compliance Technology.
In a triangular structure like the rear triangle, all elements are under tension or compression when the structure is under load. This is amplified with straight tubes. In order to give the structure more flex BMC introduced angled elements in chain stays, seat stays, fork blades and seat post. Right in front of the dropout the chain stays are massively reduced in their cross section and kinked, creating a flex zone, which acts as a pivot. The dropouts are offset to the rear, creating a torque that causes the seat stays to flex. All of this adds up to 20mm of vertical compliance, 16mm from the seat post and 4mm at the rear axle (under 1000nm load). This is 40-percent more than the SLR01.
Up front the vertical compliance of the fork is not so much due to the axles vertical movement, but in the dropouts position in relation to the fork blades. The forward kinked angle just above the dropout takes impact shock out of line with the fork blades, much like the old curved steel forks of yesteryear
First Ride
The underlying theme of the GF01 is vertical compliance – and BMC delivers. On the road it is notably more compliant than BMC’s race oriented SLR01. What sets the GF01 apart from many other bikes in the endurance category is the bikes torsional stiffness and handling performance. Power put to the pedals is transferred directly to the ground while the front tracks true and cornering is precise.
Despite the taller head tube it was still possible to get a fairly race oriented position. This aided in the bike’s climbing and descending performance. When the road turns upward the GF01 is smooth and allows the rider to remain in the saddle, spinning a low gear. Not as fast as a race-oriented machine the GF01 keeps a steady pace, but doesn’t hold speed as well. A lot of this can be traced to the large 28c tires, which add a notable amount of rotational weight.
On descents the GF01 is fast and stable. On open straight roads the GF01 is most at home with its smooth ride and large tires adding confidence and allowing the pace to be pushed. The steering is quicker than we expected allowing for respectable cornering performance. However, the tall head tube hampers aggressive cornering as it is difficult to weigh in hard on the front wheel.
First impression of the GF01 is that it is a well-engineered blend of performance and ride quality. Look for a full review in a future issue of peloton.