The new BMC Timemachine uses radical design features all in a bid to make it the fastest aero bike yet
Swiss bike manufacturer BMC has unveiled its latest aero road bike – The BMC Timemachine 01 which is a considerably updated version of the original Timemachine aero bike launched back in 2012.
The new bike will be exclusively available with disc brakes with the previous version featuring calipers and rear brake mounted on the bottom bracket.
BMC has endeavoured to make the Timemachine faster and more comfortable than the older model, however they were also keen to make a bike that quite simply, looked fast too.
BMC Timemachine: Design Process
To design the new Timemachine, BMC carried out what it describes as ‘extensive’ computational fluid dynamic studies (CFD) to refine tube shapes and profiles for optimum aerodynamic efficiency.
Following this, BMC performed wind tunnel and velodrome testing to further asses and optimise the aerodynamics of the frame and back up the CFD simulation results.
BMC also used its Impec Lab to optimise the carbon layup to maximise the stiffness and compliance characteristics of the frame in the regions where it is needed. Overall this has resulted in a futuristic design with several novel features, as well some features that have become synonymous with modern aero bikes, such as the Kaam tail tube profiles and dropped seat stays.
Visually, the biggest standout feature of the new Timemachine is the integration of the bottles and cages into the frame. The BMC engineers have done this in a bid make the frame more aerodynamic and reduce drag.
Below the cages sits a storage box, which has been designed to replace the need for a saddle pack while also reducing drag. The “aero module” as BMC is calling it has been designed to eliminate the aerodynamic penalty of attaching bottles to a bike frame.
Many early aero bikes feature tube profiles which are very aerodynamic without a bottle, but can become aerodynamically compromised once one is attached, particularly at yaw angles beyond 0º. Bike brands have started to realise that in reality, riders very rarely ride without bottles and cages and newer designs have sought to address this. One notable example of this is the Pinarello Dogma F10, with its recessed, concave down tube. By partnering with the Italian bottle cage specialists Elite, BMC has taken bottle integration one step further.
BMC claims the new Timemachine is fastest when all the elements of the aero module are fitted to the bike, with empty bottles faster than no bottles, too. However, when the storage box is equipped, the bike is no longer UCI compliant, so expect it to be removed for the races. The integrated bottle cages are UCI legal though, so we can expect Greg Van Avermaet to be using them.
BMC informed us that new bike will be shipped with the cages, bottles and storage box, which also includes a specially designed soft case to go inside. The box features internal ribs to stop the soft case rattling while riding too.
The specially designed down tube bottle cage also makes use of the new Shimano junction box, by neatly integrating in the down tube, out of the wind and for easy access.
ICS Aero Cockpit
As the leading edge, the cockpit is a crucial area for a bikes aerodynamics and BMC has paid particular attention by building on what it learnt from the Road and Teammachines.
The integrated cockpit system (ICS) first seen on the BMC Roadmachine has been adapted with a wider and thinner stem that BMC claims offers increased vertical compliance and greater lateral stiffness. There is also a specially designed ICS aero bar that blends into to the stem and is available in three widths (400, 420, 440mm).
This two piece aero cockpit design has the potential to offer greater flexibility to customers than the all in one bars and stems increasingly seen on aero bikes as it allows riders greater flexibility to chose the stem length and bar width they desire.
Functionality and practicality are important too. Split spacers mean you can adjust the stack of the stem, without disconnecting the hydraulic lines from the brakes. There is also a recess in the top tube for accommodating additional cable length. This means should you wish to lower the stem or adjust your stem length or bar width, you shouldn’t have to disconnect and re-cut cables. Clever.
The consensus among bike designers is that a disc brake caliper on the fork increases drag, so BMC has engineered and shaped the fork to smooth the airflow over the caliper – a similar design solution to that seen on the Scott Foil Disc.
The fork also has an asymmetric design to cope with the forces created from disc braking and clearance for 28mm tyres front and rear.
BMC is not making any claims about the aerodynamic performance against other leading aero bikes, as it hasn’t performed competitive testing against them. Instead, the engineers tested the new Timemachine against the brands existing Teammachine race bike.
With a protocol similar to that performed by Cycling Weekly when performing aerodynamic testing against different bikes, BMC carried out velodrome testing to asses the new Timemachine against the existing Teammachine model.
BMC performed testing at a range of speeds but has chosen to publish data pertaining to a velocity of 40kph. The reason for this is that BMC feels this is more representative of most riders who will purchase the bike. It should be noted that because drag is a cubed function, significantly bigger wattage differences would be observed at higher speeds such as 50kph.
BMC tested the new bike against the Teammachine with three riders all riding different sizes and all bikes were fitted with the same wheels as to asses the relative aerodynamic performance of the frames.
BMC claims that at 40kph the biggest saving observed was for the biggest rider, Michael Scharr, who saved 12W by riding the new aero bike. The other two riders saved 6 and 8W. As a proportion of the overall watts produced by the rider, this can be expressed as a ~3% saving in aero drag equating to an average speed increase of 1.5kph or 2 minutes saved over 40kph.
The graph below displays the aerodynamic saving of the new BMC Timemachine (fitted with the complete ‘aero module’) vs a BMC Teammachine. This experiment was performed in a wind tunnel in order to replicate the higher yaw angles seen when riding outside, typically in a cross wind.
Both bikes were fitted with the same wheels and tyres. According to BMC, at Oº yaw, the Timemachine exhibited an 11.5W drag saving over the Teammachine at 45kph. At significantly higher yaw (15º) this saving dramatically increased to 18.4W, which BMC attributes in part to the sail effect of the aero module.
BMC’s own testing claims that the new Timemachine frame and fork posses comparable levels of stiffness and compliance to that of the Teammachine SLR.
Having attended the launch of the new Timemachine I was able to take the new bike out for a couple of rides on beautiful Swiss roads. Without question, from the moment you set off it is apparent that the new Timemachine is tangibly fast.
Without performing my own comparative aero testing it’s impossible to say how it stacks up against other leading bikes, however I’d wager it to be right up there.
Such is the quality of Swiss roads, it is difficult to comment on the compliance offered by the new machine, especially as 90% of my riding takes place on the psuedo pavé generously laid out by Highways England. With regard to handling I felt comfortable throwing the bike through corners and the steering response was predictable, however I was hesitant to push on the descents owing to unfamiliarity with the tyres we were riding.
When climbing the Timemachine felt hugely capable, with excellent stiffness and no brake rub when gassing it out of the saddle. It’s slightly heavier than the Teammachine, but personally I feel I would reach for it over its lighter, but less aero brother on all parcours excluding hill climbs.
The heavy integration results in a bike that looks radical and will probably divide the judges in a beauty contest, however my take is that the kind of integration we are seeing here will become common place in the aero bikes of the future. For pushing aerodynamic road bike design BMC should be applauded.
UK pricing is still to be confirmed, with the new BMC Timemachine available in three complete bike models and also as a frameset only option.