The BMC Race Machine, Part II
Here’s the part of this bike’s geometry that is surprising: The combination of a 72.5-degree head tube angle and 4cm fork rake results in an astonishing amount of trail—6.53cm. That’s more than some of the most sluggish bikes I’ve ever ridden. It may be that what kept this bike handling with the crisp precision of a Swiss timepiece was that long head tube and relatively high bar position. The retailer from whom I picked up this demo thought that at my height (5-feet 11-inches) I ought to be on a 53cm frame. Aside from the fact that I’d never be able to sit up enough to get up a hill, there was that tiny problem of the pinched nerve and the unavoidable problem of having so much weight on the front wheel that the bike would only turn under duress. Yes, I tried it in the parking lot and the suggestion that a guy my height would ride a bike that small was, well, laughable.
Speaking of sizes, the Race and Team Machine are both available in six sizes. Top tube lengths are 52, 53.5, 55, 56, 57.5 and 59cm. Every one of the bikes features a 73.5-degree seat tube angle and 40.2cm-long chainstays. The bike with the 52cm top tube has a 70.5-degree head tube angle and the 53.5cm top tube has a 72-degree head tube angle. All other frames share an identical 72.5-degree head tube angle.
That the same head tube angle, seat tube angle and chainstay length runs through most, if not all, frames tells you a couple of things. First, it tells you that BMC saved money in tooling by not cutting as many molds. But because (to the best of my knowledge) every frame uses an identical 40mm-rake fork, four of the sizes enjoy identical steering geometry. The 53.5cm top-tube bike is close. Only the 52cm-frame falls significantly outside that geometry; it’s got so much trail that unless it’s spec’d with a 50mm-rake fork it’ll need a tugboat to turn.
While these similarities help unify the handling across most of the sizes, there is a liability to this approach. In the smallest frame a 73.5-degree seat tube angle may not be steep enough for some riders and in the biggest size that seat tube angle may be way too steep for some riders. The challenge here is that with a proprietary seatpost, you don’t have the flexibility to order an aftermarket seatpost with either no or 4cm of setback. I can envision some very disappointing fitting sessions if someone didn’t do their homework ahead of time. Details like this make the new Retül Frame Finder an indispensable fitting tool.
BMC touts several technologies in the Race and Team Machine models. First is the TCC or Tuned Compliance Concept. With the TCC the fork, seatstays and seatpost feature specific layup and material selection to allow for a certain amount of vertical compliance. I really need more miles on the Team Machine to see how much they vary between the two models, but having been on bikes that excessively stiff vertically, I can say that it is possible to make a bike that is less comfortable than the Race Machine—it really could be stiffer vertically, and I’m glad it’s not.
The ISC or Integrated Skeleton Concept is the design element that leads to the little strut that runs from the top tube to the seat tube just below the seat tube junction. It’s meant to spread impact forces, but honestly, I’m not sure what impact forces the marketing copy refers to and given that no other bike company has gone this route, I’m suspicious of the benefits it confers.
Two other design details contribute to the bike’s performance-oriented stiffness. First, the bottom bracket uses a BB30 design to all but eliminate twisting forces at the BB. Second, the fork features a tapered steerer to increase stiffness at the head tube and crown. The tapered fork is one of those innovations that came from a single company (Time) that nearly everyone has adopted. That’s how you know an idea is good. When I go back and ride my old Seven Cycles Axiom I immediately register the difference in torsional stiffness; that bike uses a 1-inch fork, and while it doesn’t feel like a noodle, the increase in stiffness when I move to another bike is unmistakable. I might not be able to quantify the difference, but that doesn’t make the perception subjective. Similarly, I can recognize features of my wife’s face in my son’s face, but I’ll never mix the two up.
With its particular constellation of features—consummate stiffness, relaxed handling and low, but not excessively low, weight—this bike is a great choice for a huge number of riders. Its handling is more aggressive than grand touring bikes like the Specialized Roubaix, but isn’t as sharp as more race-specific rides such as the Giant TCR Advanced. It’s going to serve well for someone doing group rides and gran fondos and if you want to jump in a crit from time to time, it’ll corner effectively. With two bikes so similar in design, I’m inclined to recommend the Team Machine to lighter riders while encouraging guys 165 lbs. and up to go with the Race Machine.
I’d love to get some more time on the Team Machine in order to help differentiate the two bikes further. I’ve never encountered a web site that did less to identify the differences between two similar bikes than BMC has done. I went as far as watching some videos produced of the bikes, one theoretically meant to tout the bikes’ stiffness and another that fancied itself a report on the bikes’ low weight. The two videos were identical between the two models and nearly identical to each other. Making matters worse was the fact that the only sound was a bit of sound effect; there was no voice-over.
There’s no doubt the Race Machine is a terrific bike. Honestly, my greatest criticism is their marketing copy. They’ve done so little to differentiate it from the Team Machine, the only way I can recommend one over the other is by rider weight, and I doubt that’s what they had in mind.