Cervélo unveil the new S5 Aero road bike

Well there's been a lot of talk about it, and Thor Hushovd was spotted riding something that might have been it in the Nowergian National Road Race Championships, but today they've confirmed it: Cervélo are launching the S5 aero road bike.

What we don't have at this point are a lot of facts about the new bike. We do have a bunch of photos that Cervélo sent us though, and Mat and Tony are currently hotfooting it to the Vendée to hopefully get a gander at the bike in the flesh. But for now, let's look at what we have...

Okay, so here's the full bike, side on. Let's compare that to the S3:

and also the P4:

And you can see that it's somewhere in between the two, but closer to a road-geometry version of the P4. The seat tube is sculpted round the rear wheel in much the same way as the P4, and the seat tube angle is straightened up at the top, though not so aggressively as the P4 of course. The chainstays are much wider and more flattened than the S3, and at the front the curve between top tube and down tube has been replaced with a flatter, bladed head tube. Clearance between the down tube and wheel is reduced, and the fork blades integrate into the down tube shape to improve air flow.

The bottom bracket area features the flat section you also find on the P4, which means there'll be a special aero bottle available for the frame. For non-UCI events, of course...

The down tube is flared and flattened at the bottle bosses, in order to minimise the drag if you're using a standard bottle and mount.

From the front, well... there's not much to see. Check out the scuplted head tube to minimise frontal area, it looks like Cervélo have gone with a standard 1.125" bearing top and bottom to keep the profile as low as possible. All cable routing is internal, of course.

The S5's stays are very different to the S3, much more flattened like the P4.

Cervélo haven't gone for enclosed brake callipers which is probably a bridge too far on a road bike. but they have obviously done a lot of work on tucking the rear brake away. Where the S3 had a standard bolt-through mount that's not an option on the S5 with its sculpted seat tube, so the calliper hangs from a mount that bolts into the frame. Again, the surfaces butting up against the brake are flattened to try and improve airflow around the bike as a whole, not just the frame.

This bike is going to appeal to triathletes as well as road racers. It comes with a two-position seatpost that will steepen up the seat tube for a better tri position.

The seat clamp is hidden in the frame, giving very clean lines around the seatpost.

So what does all this work mean in real terms? Well, Cervélo have been testing the bike extensively of course, and here's the figures they're quoting:

Aerodynamic Savings Over Cervélo S3:
· 36.8 seconds over 40k
· 0.92 seconds per kilometer
· 92 grams of drag
· 9.2 watts of power savings

So, a nearly 10W saving over the S3; we're not sure what speed that's for. 36.8 seconds over 40km. Those are some worthwhile savings if Cervélo's test data is borne out in real world scenarios. It might not be the difference between winning and losing on any given day – Hushovd only managed third in the Norwegian champs on his S5 – but those incremental gains would be beneficial over the course of a three week tour...

And how much will it cost? Lots and lots. We don't know for sure, but since the P4 and S3 framesets are three and a half grand a pop, we'd expect the S5 to hit the shelves costing at least that, and probably a bit more. All those wind tunnel hours don't come cheap... It's also been granted a UCI sticker by the blazers of Aigle, so that means you'll almost certainly be seeing the S5 in this year's Tour de France. Stay tuned for more!