Tour de France stages average more than 100 miles in length so riders need to be comfortable; let’s check out the saddles that they're using.
Judging by what we've seen this year, it looks like ever more riders are going for shorty saddles designed especially for those who spend a lot of time in an aggressive ride position – so racers, then.
The majority also favour a pressure-relief channel or hole down the centre.
Prologo sponsors seven teams in this year's Tour de France and has produced saddles in relevant colours, available to buy in limited numbers.
These ones are for Astana and Groupama-FDJ...
...and this one is for EF Education First.
In each case the saddle is a Dimension with Nack carbon rails and a PAS pressure relief channel. The Dimension is a short saddle, measuring 245mm from nose to tail.
GC contender Jakob Fuglsang of Astana opts for the NDR version of the Dimension. NDR saddles are designed for mountain biking and endurance riding, coming with high-density padding that's 3mm deeper than normal. You can imagine that this might be welcome over the course of a three week race. The saddle also comes with side protectors to help avoid damage.
UAE Team Emirates' Dan Martin goes with a Prologo Zero C3. It's a flat saddle with a carbon composite base and a claimed weight of just 143g.
Thibaut Pinot, sitting third in GC at the time of writing, goes with a Prologo Nago Evo featuring a French tricolore and his own logo. It's a semi-round saddle with Prologo's CPC Airing (the distinctive panels of raised material that you can see) designed to provide shock absorption and cooling, reduce vibration and improve grip.
CCC riders use saddles (and wheels and tyres) from Giant's sub-brand Cadex. The Boost on Patrick Bevin's bike features a composite base with integrated rails, and a truncated nose. The length is 246mm, compared to the UCI's minimum permissible length of 240mm. Cadex claims a weight of just 138g.
Movistar's Alejandro Valverde uses a Fizik Antares 00 with carbon rails and a cover that features rainbow stripes in recognition of his status as world road race champion.
Valverde's saddle is positioned as far forward as possible on its rails.
Geraint Thomas uses a Fizik Arione R1, a very long (298mm), flat saddle with braided carbon rails. G has the same model on both his Pinarello Dogma F12 road bike and his Bolide time trial bike. Those marks on the cover are to help the mechanics get the position correct for each rider.
Many riders like a saddle with a short, well-padded nose for time trailling to provide comfort and freedom of movement while in an aero position. Nicolas Roche has a Pro Aeroful with hollow stainless steel rails and a carbon-reinforced polymer base.
The Ares time trail saddle is no longer in Fizik's range but you still see it on the bikes of some professionals, such as Movistar's Imanol Erviti. The central panel on the cover is designed to stop the rider slipping.
Bahrain-Merida is sponsored by Prologo but team member Vincenzo Nibali is a long-time Fizik user. That's why his Antares 00 bears no logos.
Some of the Bora–Hansgrohe team choose Specialized's Women's S-Works Power with Mimic over any of the men's saddles in the range. The short nose is made up of two different densities of memory foam to relieve pressure, while the shell and rails are carbon-fibre.
Six-time Tour de France points classification winner Peter Sagan goes with an understated Specialized S-Works Romin Evo. The shell and rails are carbon-fibre here too, but the shape is entirely different with a cutaway centre for pressure relief. The Romin Evo is available in two different width options, Sagan's 143mm version weighing a claimed 134g.
Selle Italia is well-represented in the pro peloton. Team Dimension Data's British rider Steve Cummings uses a Novus Boost Kit Carbonio Superflow with carbon/ceramic rails and double density padding.
Edvald Boasson-Hagen prefers an SLR Kit Carbonio Superflow with a huge cutout in the centre. The shell is made from 30% carbon composite with a nylon polymer. Boasson-Hagen is another rider who has his saddle pushed as far forward on its rails as possible so that he's positioned over the bottom bracket more.
Katusha-Alpecin's Alex Dowsett has a Selle Italia SP-01 Kit Carbonio Superflow on his Canyon Ultimate CF SLX. The standout feature is what Selle Italia calls the 'suspension link movement'. The two sides of the saddle are connected only at the nose and indirectly via the clamp at the top of your seatpost. The sides are entirely separate from one another elsewhere. Plus, the shell is divided into upper and lower sections at the back, the rails connecting to the lower section.
The upper sections of the shell, not connected to the rails, are free to flex more than usual. The two sides can also flex independently of one another.
Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, 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 winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.