Take a look at the bikes being used by Garmin-Sharp's Tour de France stage winner

Team Garmin-Sharp's Dan Martin won yesterday's stage of the Tour de France from Saint-Girons to Bagneres-de-Bigorre on a Cervélo RCA. This is the almost identical bike belonging to teammate Christian Vande Velde…

The RCA is Cervélo's lightest ever frame, coming in at a claimed 667g (for a 54cm version, which is what Dan Martin rides, with paint and hardware). It features an aero shaped down tube, hollow carbon dropouts, an integrated power meter magnet and a new 3M Powerlux resin.

That resin is infused with 40% nano silica particles which is said to make the carbon structure more resistant to cracking or buckling. The idea is that this allows Cervélo to build the RCA superlight without compromising the strength.

The down tube is what Cervélo call their Squoval 3 design, with an aero-shaped frontal surface to smooth the airflow. They claim this new tube shape saves 7.4 watts compared to their Squoval 2 design. The carbon dropouts are hollow to save 5g and the cables pass through them to keep the routing clean.

In a first that we know of, Cervélo have integrated a magnet for power cranks into the down tube. It's included in the layup procedure.

Interestingly, Irish rider Dan Martin had been on the R5 on Saturday's first Pyrenean stage. This one, in fact, that we had a good poke around when we went visiting Garmin-Sharp's team hotel before the start of the race.

As we told you last week, Garmin-Sharp have a special edition finish on some of their bikes to mark the 100th edition of the Tour de France.

The R5 is superlight and superstiff, although it doesn't use the RCA's 3M Powerlux resin and the down tube is the second rather than third generation Squoval design. That didn't seem to hold Martin back to much heading into the finish - this is still an incredibly good bike.

Unusually, though, among top-end performance bikes, there is not a Di2 specific version of the R5. Garmin-Sharp do use Shimano's electronic shift system but the cables have to run externally via stuck-on housings, and the cable-stops are left redundant on the down tube. It's not the neatest option out there. Cervélo do have internal cabling on their S5 aero road bike and it can only be a matter of time before the R5 gets a redesign to incorporate this feature.

The wheels are Mavic's extremely light R-Sys SLRs and those are Mavic's Yksion Grip Link tubular tyres stuck on there.

3T make their products in three distinct ranges: Pro is the most affordable, Team is the mid-level, and Ltd is the top end. You might have throughout that the pro riders would always go for the Ltd kit but there's none to be seen on Martin's bike. He uses a 130mm aluminium (AL 7075 T6) ARX-Team stem and a Rotundo Pro aluminium bar. Loads of the pros go for aluminium bars and stems because of the stiffness they offer. Plus, with bikes easily able to make the UCI's 6.8kg minimum bike weight limit, there's no need to save every gram.

The seatpost is a Doric Team which no longer exists in the 3T range (although you can still get them in the shops) while the Fizik saddle looks like an Antares 00 – a stiffer and lighter version of a standard Antares braided saddle, weighing in at just 135g.

Garmin-Sharp are sponsored by Rotor and those are the aero Flow cranks that we first saw at last year's Tour. Dave reviewed a pair recently. It's all about the marginal gains. Apparently.

Bottle cage fans will be interested to hear that those are Arundel Mandible cages on Dan's bike, by the look of it. They're not cheap at £45 a throw, but they are lightweight (28g) and they hold your bottle very securely. Even if you crash, your bottles are likely to stay in place.

Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.