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.

The proprietary seatpost is cool looking but could make fitting the bike difficult for some riders.

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.

Some of the co-molded joins are plainly visible.

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.

BB30 allows designers the ability to make a BB wider and, therefore, stiffer.

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.

The wishbone seatstay isn’t as thin as some of the new designs, ensuring it will always be fairly stiff.

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.

 

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8 comments

  1. Mike

    Thanks for the review! I appreciate the comments on the geometry. I have been, frankly, confused by their choices and wondered how they shake out on the road. It was interesting to see the video reviews of the SLR01 and the Bianchi Sempre on the Peloton site…it appears that the two companies have gone in opposite directions for racy geometry: Bianchi with steep angles and longer chainstays, BMC with slack angles and short stays.

    Now, I love my older Bianchi and one of my riding buddies is enjoying his new BMC. I wonder how differently they handle? We’re not the same size, so a quick switch wouldn’t help.

  2. velomonkey

    53cm at 5’11″ – does this guy even know bikes! That seems absurd to me. It seems more often than not at the tall end we are often between 2 sizes – I’m 6’3″, but mostly torso. I set my bikes up from the cippo days – top tube and a long stem. I could possibly do a 58cm top tube and a 140cm stem and show the right amount of post on a 57, but a 57.5 top tube might be too short. Conversely I’m on a 58sloping colnago with a 59cm top tube and 130mm stem, I could have gone one size smaller and showed the right post, cause right now it’s not much.

    I’ll definitely check into this bike – though it was good to see Schar ripping it up on a BMC team machine at 6’5″, then again the guy is 165 pounds.

  3. Spencer

    Great review! I just bought one of these frames after crashing my 2008 Pro Machine – frame is being shipped as I type. I agree that the frame geometry for BMC’s bikes can be tricky. There is this trend in the industry to lengthen the head tube and include proprietary seat masts which seems to handcuff bike fitters. Lots of hand wringing went into the selection of my new frame and I am still nervous that I will be racer-slammed in the front with a -17 degree stem and my saddle pushed way back on the seat mast when I finally get it built up. I considered buying a Team Machine last summer about this time but when the only seat mast available was a zero offset model I decided to pass (they have since introduced a setback model after the entire Pro Team was spotted riding them). What is the offset in the seat mast on this frame? (another useful nugget of information seemly missing from the BMC website) I rode a 55 cm Pro Machine (I too am about 5′ 11″). The top tubes on the two frames are identical and the head tube on the Race Machine is about 3 mm taller. The big difference is the 25 mm offset on the seat mast of the PM and the fork (as you pointed out)

    Thanks again for the review and pictures!

  4. Wayne

    BMC seems to have a believe in the geometry across the larger sizes (which I like) but smaller riders should just get stuck with a trail which the company believes is too long. I guess it works if people will buy it.

    Thanks for mentioning this in your review. It is an important point for smaller riders to consider. 65mm trail….

  5. Mike

    I’m still stuck on the front end thing…I have a light touring bike that has a slack head tube and lots of trail, and it really seems affected by crosswinds–it blows away from the wind, which is unnerving. With non-aero wheels, I attributed this to the geometry.

    Maybe I need to go test ride a BMC at the local dealer.

  6. mark

    One thing to consider with the smaller frames is that the shorter wheel base sometimes benefits from the stability of a slacker HTA. My Giant TCR has a 72 degree HTA while the larger sizes have a 73, and it corners just fine while being far more stable at speed than my old Lemond.

    That said, 70.5 is mountain bike geometry and seems a misguided attempt to avoid toe overlap in the small frame sizes. Having dealt with toe overlap on every road bike I’ve owned, I can say quite confidently that it’s entirely a non-issue and is only ever noticeable when track-standing at stoplights.

  7. AM

    Wondering whether you had any more recent insight into differences between the Team Machine and Race Machine. I agree that BMC has a perplexing lack of clarity on this, aside from the ~100 grams. Anyway, thanks for a nice review, and look forward to hearing from you.


    1. Author
      Padraig

      AM: Sorry to say I haven’t had any more time on the Team Machine other than the one ride at Interbike, so no new insight. I’ve got a friend who owns both the Team Machine and the Race Machine and he rides the Team Machine most days. Says it’s more comfortable.

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