This article originally published on BikeRadar
BMC knows how to make bikes ride like silk. With the 2011 launch of the TeamMachine they introduced their Tuned Compliance Concept (TCC), where a more elastic composite material and layup is used in non-key areas to boost comfort, and this has now proliferated throughout their line. The latest model to benefit from this technology is the new 2013 TeamElite TE01 29.
This 29in-wheeled cross-country race rocket builds on the design of the GranFondo GF01 classics machine, launched just two weeks ago. It shares key features of that bike, including the offset between the top tube and seat stays, the tubing kinks that are specifically engineered as flex points, the offset dropouts and the TCC zones.
BMC says they've focused on three key areas with the new TeamElite: geometry; tube shape, size and layup; and weight. The company targeted sub-1,000g for the TE01 29 and claim the medium frame tips the scale at just 980g.
The end product is a unique, early release 2013 package built with SRAM X0 shifting, Easton EA70 wheels and cockpit, and 2013 FOX Float CTD FIT fork, priced at US$5,499. Our medium size demo bike weighed in at 23.23lb (10.53kg) with our own Shimano XT pedals. BMC say they'll fulfill all dealer demand for this model with a one-time order, and that additional models and frame-only options won't be available until the fall trade shows.
BMC’s TE01 feature trifecta: Geometry, compliance and weight
BMC spent the first year of the carbon TE01 29’s development working solely in aluminum, and specifically on the bike’s geometry. For much of 2011, Steve Ettinger, a then U23 rider for the BMC developmental mountain bike team, put both training and race miles on a white alloy prototype.
This was the last of three different geometry mules BMC used along with Cane Creek’s AngleSet to arrive at their ideal 29er metrics for cross-country racing. The 'BWC' (Big Wheel Concept) geometry they arrived at is: 70° head tube angle, 429mm chainstays and 65mm bottom bracket drop.
These are paired with a long top tube and very short head tube – 90mm on the small frame, 100mm on the medium and 110mm on the large. This setup allows racers to get low and also enables BMC to run with a very contemporary concept: relating stem length directly to head angle (rather than rider height). As a result, all three sizes of the TE01 comes with 70mm stems and 685mm bars.
TCC (Tuned Compliance Concept)
TCC (Tuned Compliance Concept) refers to the way the TE01 29’s carbon tubes have been engineered to be torsionally stiff with vertical flex. To achieve this, BMC pays close attention to the frame shape, carbon layup, tube sizing and materials used throughout each chassis – the goal is to offer the same feel consistently across the three frame sizes.
Looking at the frame it's more obvious to see what TCC means. The lower chassis is massive, in order to resist torsional twist between the wheels. There's a tapered head tube, a huge down tube, an oversize press-fit BB92 bottom bracket and big, boxy chainstays that connect to the rear wheel with beefy all-carbon dropouts. These components are all designed to add stiffness, in order to better handling and pedaling efficiency.
From the 1.125in top headset bearing backwards it’s a different story. The top tube tapers dramatically towards the seatpost and it's both kinked and offset from the chainstays where it connects to the seat tube. The rear ‘triangle’ is more of a trapezoid, with an angled shelf that supports the dropouts and rear brake mount, and this is where much of the bike’s claimed 10mm of vertical flex comes from. (BMC measures this by fixing the bike's front and rear dropouts and loading the seat with a 1,000N force, which is roughly a 220lb weight.)
By offsetting the top tube/seatstay interface, BMC set the stage for their TCC design; the kinks, tube sizes and shapes are all part of the design as well
Moving to the micro scale, TCC influences tube sizes as they pertain to the three sizes of the frame, and also the carbon layup, which has been tuned to maximize this dichotomy between vertical flex and torsional stiffness. BMC says they tried 10-plus layup iterations before settling on the final schedule.
TCC is also carried into the design of the now-narrow 27.2mm seatpost. BMC offers three different posts with the TE01 29, which vary by offset – 3mm, 18mm and 30mm. Each post is constructed to offer the same amount of flex and account for the additional leverage exerted by the larger offsets.
BMC says once the geometry was dialed in and the desired amount of flex achieved, they set out to meet the metric every cross-country racer uses as their barometer of a good race bike – its weight. The result is a 980g claimed weight for the medium frame, including all hardware (post mount brake nuts, integrated chain watcher, cable guides). BMC say this impressive figure was achieved through material selection and an intensive layup ‘optimization’.
The details: Slick brake mount and chain catcher, impressive finishing attention
BMC completes the TE01 29 with an impressive slew of details. They've molded the post-mount brake mount entirely from carbon (it houses pockets for replaceable cylindrical nuts), integrated a front chain catcher to protect the bottom bracket shell and down tube, and used a direct-mount front derailleur to help achieve the short chainstays.
The front derailleur housing uses short runs and conventional cable stops to save weight, while the rear derailleur (which has a replaceable hanger) relies on a full length of housing, which mounts alongside the rear brake line. Another forward thinking nicety is the InSet headset configuration, which allows use of a Cane Creek AngleSet – yes, BMC tested to find their favorite head angle but if you don’t agree you can modify it yourself.
The rear brake caliper nestles between the seat- and chainstay
The hour of power: A first ride on the TE01 29
At 5ft 9in, we fit perfectly on the medium bike (with the 3mm offset post) without feeling the need for a stem length change. Like BMC's road bikes, the TE01 29 rides smooth but maintains a crisp acceleration. Larger peers complained about a slight bounce coming from the frame but we experienced no such problems. The front end was adequately stiff, though not overtly, and we found ourselves wrestling with a slight bit of understeer – nothing we couldn’t work through with another hour on the bike, though.
Bottom bracket height, or rather drop, is a huge factor in how well a big-wheeled bike rides and BMC seem to have honed in on that, ultimately using it to their benefit. Getting the front end in the air was relatively easy, likely helped by both the bottom bracket placement and the short chainstays. After just more than an hour ripping around the trails surrounding the Laguna Seca Raceway, we're able to give the bike a hearty thumbs up, pending a longer term test.