"The 28mm tire spec was the primary consideration when forming the basis of the GF01 project."
Versatility is beginning to creep into road bike design and construction. Versatility meaning bikes intended and created with multi-purpose use in mind, not just built for smooth roads and pro road racing. Bikes when in the hands of a pro, capable of winning classics on cobbles in treacherous bike-hammering conditions, yet at the same time ready for anyone to tackle the next big Gran Fondo event, or perhaps that long training ride where comfort is key. A bike you can ride all day and benefit from a bike that soaks up the bumps - a go anywhere machine. Want to head off the bitumen and explore dusty roads, you now have a choice. A stable, comfortable bike which aids fatigue reduction yet will steer where you point it.
BMC are moving fast in the development of their range of road bikes, their latest offering, the granfondo GF01. Last week at the Australian launch of the BMC granfondo GF01, the bikes were taken off road and onto a section of gnarly single track. The bikes even coping with a one metre drop off, with test riders making full use of the opportunity to give these machines a bit of rough treatment and test their capabilities. The GF01 was a hit, everyone on board one of these bikes thought they did the job over and above what they would have expected.
BMC set out to address three key requirements when creating the GF01, these were vertical compliance, ergonomics and ease of use. A direct benefit of considering these three requirements was to create a bike which is comfortable on long rides yet not necessarily only a race machine, the GF01 was raced at Paris Roubaix this year though. The GF01 is aimed more towards the recreational aspects of cycling, like the title Gran Fondo suggests. Easy handling was a key consideration for those not used to a more aggressive pure road race setup. The GF01's geometry is intended with stability being a prerequisite. A more upright position can be achieved, so the bike is ideal for riders new to the sport of cycling. More stability combined with comfort, yet the stiffest bike ever produced by BMC - the GF01 is meant to be a great alternative for heavier riders which should also translate to safer handling at high speeds. BMC have created a user friendly bike which should instill confidence in riders of all levels, a go anywhere machine for all occasions. The GF01 weighs slightly more than the Team Machine SLR01 plus torsional stiffness, bottom bracket stiffness with a BB86 press fit spec as well as comfort are all greater than the SLR01. (A 54cm GF01 frame weighs 995gr) TCC or Tuned Compliance Concept was first introduced with the SLR01, now TCC has been adapted for comfort in the GF01 alongside what BMC call angle compliance. Angle compliance is achieved via the "bent elements" or kinks. The GF01 is claimed to have 40% more compliance than Team Machine SLR01 - yet highest lateral and torsional stiffness, making the bike more comfortable to ride without sacrificing on performance factors. The challenge was to increase vertical compliance without compromising braking efficiency and power through the drive-train. Solution, introduce a "Bent Element" thus making the structure more flexible. Kinks were introduced to four key areas - the seat post, seat stays, chain stays and fork blades. An angled fork blade absorbs impacts better over a range of obstacles.
Rear Dropouts were massively modified - a flex zone is created at the chain stay to dropout junction by reducing the size of the chain stays and offsetting the drop outs to the rear - the drop out offset causes a torque loading through the seat stays causing them to flex, building in more vertical compliance. A reduced cross section in the fork and seat stays allows for further flexing.
A 27.2 seat post specification, by using a long thin seat post more compliance is built in. BMC choose the best compliance, not the softest. There are 3 setback options 30 mm, 18 mm, 3 mm, all setback options are tuned to give exactly the same amount of compliance, 18 mm setback comes as standard. The GF01 has a higher stack and shorter reach achieving a more upright position. Given these options the GF01 is going to give a wider range of choice for those not wanting the most aggressive race oriented setup. The riders age and flexibility plus core strength / stability comes into play here too. Imagine you are choosing a bike and don't intend to race, perhaps you are older and not as flexible as you once were, or perhaps you are coming back from an injury and need a bike which is comfortable and adaptable to your recovery - the GF01 is ready right out of the box, to customise your bike fit and provide a great alternative. Once out on the road the GF01 should be more user friendly.
Big cross sections of down tube, chain stays head tube and fork crown - provide maximal lateral and torsional stiffness. Note that geometry is key here too, it's not just about compliance and stiffness, BMC have adjusted the geometry with stability and comfort in mind.
Other features include an inbuilt chain catcher. BMC have added "dual transmission integration" , allowing easy installation of either mechanical or electronic group sets - see images. To further enhance comfort wide 28mm tires are standard and increase stability - riders at Paris Roubaix were using these inflated to approximately 4.5 Bar depending on the rider. Higher pressures in this circumstance don't necessarily add performance nor outweigh the need to stay upright. The 28mm tire spec was the primary consideration when forming the basis of the GF01 project.
Feedback so far is that the GF01 is everything that BMC set out to achieve. I haven't had the opportunity to ride one of these bikes yet and as soon as this happens I'll report back here. If you're in Australia and keen to check out the new BMC GF01, first delivery should hit these shores sometime in August.
All BMC bike images by Robert Cobcroft