Trek launch all new Speed Concept time trial bike
Now lighter, faster, more adjustable and easier to assemble
Trek have updated the Speed Concept time trial bike for 2014, their new design, they claim, lops 437g off the frame weight of the previous version, while improving aerodynamics in a precise range of yaw angles and reducing frontal area - making it faster in real world riding condition. Trek also say the new Speed Concept offers improved fit and adjustability and reduced assembly time.
The Speed Concept has been around for a few years. Mat tested the previous incarnation, the Speed Concept 9.9 (you can read his review here). Trek focused their time on looking at real-world wind conditions, using sensors to gather data from Ironman courses. They say they have identified a precise window of yaw angles (-12.5 to +12.5 degrees) most likely to be encountered when riding a time trial, and with this data used CFD and wind-tunnel testing to improve the aerodynamics.
It’s clear Trek spent a lot of time using the Hawaii and Arizona Ironman courses to develop the new Speed Concept. A rider who averaged 20mph on the previous Speed Concept will save 99 seconds on the Hawaii course, and 148 seconds on the latter course by riding the new version, according to Trek.
Also, Trek took Fabian Cancellara to the Valencia Velodrome to validate their claims in the real world. They say that, "The new Speed Concept saved Fabian the drag equivalent of 30-40 seconds in a one-hour time trial."
Obviously, a one-hour time trial takes one hour, no matter how fast you ride it! What Trek are saying is that if it took Cancellara to ride a given distance in an hour on the previous Speed Concept, he'd cover the same distance in 59:20 to 59:30mins on the new one.
Sounds quick, then. Trek have modified the Kammtail Virtual Foil (KVF) tube profiles (with the trailing edge chopped off), updated the shape to improve aerodynamics in a wider range of yaw angles compared to the previous bike. They’ve added ‘fillet’s between the main frame tubes to increase side surface area to reduce drag at higher yaw angles, which also act to stiffen the frame.
There’s a new fork, with an airfoil rather than KVF shape, which Trek say causes only a small weight penalty but results in lower drag design. The design has a 6:1 high-aspect-ratio which makes it UCI-illegal. Trek do appear to have designed this bike for Ironman competitors. We assume they’ll be a 3:1 fork for road events.
Trek have also reduced the frontal area - down 30% they say and 13% in the seat tube and down tube - all without any reduction in stiffness, according to Trek's men in lab coats. Another aero change that is UCI-illegal is the for triathletes only Speed Fin, an aero cover for the rear brake, with a tail to improve aerodynamics. There’s an integrated bridge to stiffen the brake as well, to improve braking performance. The UCI compliant Speed Concept has this tail removed so you can go a bit slower, but be UCI race legal. Thanks UCI!
All cables are routed internally, and the battery for a Shimano Di2 groupset is housed inside the frame.
Trek have managed to reduce the assembly time required of the new bike, with fewer parts. They say the build time is half what it was before. They also cite easier adjustments as a result, so getting the correct fit should be easier. there’s a lot less bolts on the stem, pad holders and extensions. The seatpost now has a simple two-bolt clamp.
Retaining the same stack and reach measurements as the previous bike, they’ve increased the range of reach significantly. They’ve moved the base bar forward to increase knee clearance and the brake levers shift back 30mm to they’re easier to reach. The bar extensions are available in four versions (S-bend, straight, ergo and short ergo) and they each offer 40mm of adjustment.