Video pro bike: Markus Zberg's BMC Racemaster SLX01

Aluminium-carbon creation for stiffness over lightness

James Huang/BikeRadar.com

Published: April 1, 2009 at 2:08 pm

Markus Zberg's BMC Racemaster SLX01 isn't the lightest bike in the pro peloton at 7.41kg (16.2lb) but BMC says the primary goal in designing their latest road frameset wasn't shedding grams but maximising stiffness.

How did they do it?

While most other companies concentrate on tweaking their carbon construction methods, BMC has reverted to using aluminium for the SLX01. Hydroformed and triple-butted 7005 aluminium is used for the seat tube, bottom bracket shell, chain stays, dropouts, and majority of the down tube. To make for a more rigid backbone, the down tube runs the full width of the bottom bracket shell, the seat tube is similarly flared at its base, and the tall chain stays are widely set.

BMC does use carbon for the Racemaster's top half, which includes the seat stays, T-shaped top tube, head tube, and part of the down tube in order to shave a few grams and add some rider comfort. Save for the bottom bracket shell, all of the other joints are bonded in place and the complete package is distinctive, especially when wrapped in the special paint job to celebrate Zberg's Swiss national road title.

The Racemaster may be impressively rigid but its weight is less inspiring: the frame alone is roughly 1400g and the matching fork adds another 520g.

Zberg's premium build package keeps the overall weight respectable, though, owing in no small part to Campagnolo's brand-new Record 11 group. In addition to being lighter than in years past and adding an extra cog out back, Campagnolo has also given its Ergopower levers a curvy new shape and unique multi-density 'Vari-Cushion' hoods for what is quite possibly the most comfortable perch in the peloton. Interestingly, Zberg prefers his levers positioned a long way down on the bars.

Campagnolo has also revamped the front and rear derailleurs for additional rigidity - making for snappier shifts - and a new coating on the more narrowly spaced chainrings add durability. Though narrower, Campagnolo says the new chain is stronger, too.

These wheels are badged at dt swiss but the rims are carryovers from easton since dt swiss still doesn't offer a deep-section tubular.: these wheels are badged at dt swiss but the rims are carryovers from easton since dt swiss still doesn't offer a deep-section tubular. - James Huang/BikeRadar.com

Zberg's bike features DT Swiss-badged Easton deep section carbon rims

Fitted at either end is a set of carbon deep-section tubulars conspicuously tagged with enormous DT Swiss logos and wrapped in Continental Competition Pro Limited Allround tires. The only problem is that DT Swiss doesn't actually offer deep-section carbon rims and these are, in fact, Easton carryovers from last year. DT Swiss does make the superb 240s front and rear hubs as well as the Aerolite bladed stainless steel spokes.

Easton also provides the semi-anatomic EC90 SLX3 carbon bar and forged aluminium EA90 stem, while seating arrangements come courtesy of Selle Italia's ubiquitous Flite Team Edition and BMC's own Streampost 73.5 carbon seatpost, which foregoes a conventional clamp in favour of a clever internal wedge.

Rounding things our are Speedplay Zero Titanium pedals, decadent Elite Custom Carbon bottle cages, an FSA integrated headset, and a Cateye Strada Wireless computer.

Zberg's BMC Racemaster may not be ultra-light but the added weight didn't seem to hold him back much in the Tour of California's eighth stage. There he crested Millcreek Summit with a ten-man breakaway and the frame's rigidity may have come in handy as the group jockeyed for position on the finishing circuits of Pasadena. But it wasn't ultimately meant to be as the Swiss rider missed the decisive move and finished fourth on the day.

Marcus zberg's bmc racemaster slx01

Full specification

Critical measurements