The 2021 Tour de France is not far away with the Grand Départ taking place on June 26 in Brest.
The race for the yellow jersey will likely be decided on the mountains of the Alps, Massif Central, and the Pyrenees, but which ones could be the most decisive?
There are always stand-out mountain stages in every edition of the Tour and the 108th running of the event is no different, including a mind-boggling double ascent of Mont Ventoux, the Tourmalet, and some of Andorra's highest mountains.
Last year's race showed that anything can happen right up to the penultimate stage, and it is vital riders don't lose time at any point otherwise it could be the end of their challenge for the title. Primož Roglič (Jumbo-Visma) found that out the hard way in 2020 when Tadej Pogačar (UAE Team Emirates) not only ripped yellow away from his fellow Slovenian but also put an extra minute into him for good measure on the stage 20 time trial.
So what mountain passes could see the race flip on its head? Maybe even see the race all but won... Well, we've put together a list of some of the obvious and some of the lesser-known climbs that could change the shape of this year's race.
What will the teams use in the mountain stages?
For these stages, any unnecessary weight will be unwanted, however it's now known that aerodynamics still play a key role even with climbing, meaning that many teams stick to the same bike throughout the Tour de France, the time trial stages being the exception.
So don't be surprised to see that sprinter Mark Cavendish will be riding the best lightweight bikes in the shape of the Specalized S-Works Tarmac SL7 for both the flatter sprint days and the gruelling mountain stages in order to take advantage of any free speed, especially as his bike will weigh in at around the 7.2kg mark, the UCI legal weight limit is 6.8kg (14.99lb).
The biggest equipment changes will be in the form of teams selecting the best road bike wheels and best road bike tyres for the stages. The decisions will be made on the day depending on road surfaces, weather and how technical the descents are, balancing weight, rolling resistance and grip requirements.
It's also likely that teams will be making kit swap outs, choosing some of the best road bike helmets that are lightweight and breathable, and likewise with clothing. Riders will always don the best clothing, but in the mountains, especially if it's a hot day, it's likely that the best cycling jerseys will be specifically for climbing, and will be aero fitting, have minimal bulk, be mainly mesh, and leave little to the imagination.
The best bib shorts for a day in the mountains come down to rider preference, with many opting for a pair that offers plenty of comfort for several sweaty hours in the saddle.
Mûr de Bretagne - Stage two
Sure it's not by any means the biggest climb in the route for any race, never mind this year's Tour, but the Mûr de Bretagne could be the first major shake-up of the GC contenders, especially as the peloton will tackle it twice.
At 2km with an average gradient of 6.5 per cent, it doesn't sound that bad, but with a maximum gradient of a leg-screamingly-steep 13.4 per cent for 100 metres, its easy to see why its a favourite of the likes of Dan Martin (Israel Start-Up Nation), the last winner on the climb in 2018.
Looking at the race start list so far the likes of Mathieu van der Poel (Alpecin-Fenix), Julian Alaphilippe (Deceuninck - Quick-Step), and Wout van Aert (Jumbo-Visma) could use their explosive acceleration to go for the win and maybe the yellow jersey on this climb.
But it's the gaps that are the important one, not only do the riders need to tackle the Mûr twice in the finishing circuit, the race also takes on a very short steep kick just after the first passage of the climb. This means that a group could get away and potentially stay away if it has the right makeup. GC contenders will have to be on high alert.
This turned out to be the case as it was Van der Poel who attacked both ascents to take maximum bonus seconds to take the yellow jersey. A break didn't stay away but Van der Poel put in a masterful display for yellow and the stage win.
Col de la Colombiere - Stage eight
It may not match the stature of the Grand Colombiere in any way, but the Col de la Colombiere is still a challenge that could give a few GC riders a nasty surprise.
The climb is the last of a day that sees the peloton battered by eight climbs, albeit with just the last three categorised. But the Colombiere on its own is a tough challenge. At 7.5km long with an average gradient of 8.5 per cent, this is the final kick before a descent to the finish in Le Grand-Bornand. The last winner there was Alaphilippe; maybe we will see the same again in 2021?
Tignes - Stage nine
The next day after the Colombiere, the first major mountains day beckons the riders. Five climbs, all categorised, line the route but the toughest and longest of the day is the final climb up to the ski resort of Tignes, a climb that was meant to feature in the 2019 race before it was hit by extreme weather, handing the yellow jersey to Egan Bernal (Ineos Grenadiers) on the day.
The climb is the first of the race over the 20km mark. At 21km long with an average gradient of just 5.6 per cent, it's more of a grind up rather than the gradient deciding the race. It does kick up towards the end of the climb with gradients heading close to 10 per cent.
These sorts of climbs suit riders who can set a very strong pace and put in a surge to the line, such as Geraint Thomas (Ineos Grenadiers). Unfortunately for the British rider, he is unlikely to distance the likes of Roglič and Pogačar here if they are on the same form as last year.
Mont Ventoux - Stage 11
The 'Giant of Provence' is back at the Tour de France after making multiple appearances at the Tour de la Provence and, of course, the Mont Ventoux challenge. It comes back to the Tour with a bang as the peloton take on the monstrous climb twice.
Ventoux will be ridden up on two different sides with the first ascent from the Sault side; a very long 24.3km at an average of five per cent. It does join the road we're used to seeing at the famous Chalet Reynard for the final 5km of the first climb.
They then arc back around to take the climb on from the more traditional side from Bédoin. This classic ascent is 15.7km at a more brutal average of 8.8 per cent.
The attacks will likely come on the second ascent of the climb before a rapid descent to the line in Malaucène. This absolutely has to be one of the best places to put a few tactical riders in the breakaway to potentially have on the final climb.
Col de Saint-Louis - Stage 14
Definitely one of the lesser know climbs. The Col de Saint-Louis is still a potentially vital climb in this age of racing.
The 4.7km climb is a steep one with an average gradient of 7.4 per cent. It will suit the racing style of the likes of Pogačar and Roglič but it could also see riders like Richard Carapaz (Ineos Grenadiers) gain time.
Thomas and other power climbers will have to be careful and try to limit their losses on the descent and the flat to the finish in Quillan 18km after the summit.
Port d'Envalira - Stage 15
The highest point of the entire Tour de France is, in fact, not in France at all. The race heads into Andorra and to the altitude of 2408 metres above sea level.
The climb isn't particularly long at 10.9km with an average gradient of 5.9 per cent. But you could say the climb is around 16km due to the climb of the Col de Puymorens coming just before.
It could also be a perfect launchpad for an early move with a long descent down before tackling the Col de Beixalis, which also has bonus seconds on the top then a descent down to Andorra-de-la-Vella.
Col du Portet - Stage 17
The climb that finished off the stage which had the bizarre grid start and a distance of under 100km in 2018. This time it is at the end of 178.4km with two climbs coming before it.
It is a brutal climb and summit finish at 16km with an average gradient of 8.7 per cent. This could see a breakaway stay away, it comes at that point in the race. However, that does not take away the potential GC battle behind.
This stage really gives off vibes of the Col de la Loze stage that was won by Miguel Ángel López (Movistar) and also saw Roglič put time into Pogačar, but ultimately it was not enough.
Col du Tourmalet and Luz Ardiden - Stage 18
Whether or not the main GC riders decide to hit out early on the Tourmalet is unclear. If they do, the race could be all over the mountain with huge time gaps, but anyone going on the attack has to have astonishing legs as after that they need to take on the climb to Luz Ardiden.
The Tourmalet is 17.1km at an average of 7.3 per cent with a pretty similar distance down the other side towards Luz Ardiden.
Kicking up to the ski station has almost the same average gradient as the Tourmalet but over 13.3km at an average of 7.4 per cent.
It is one of the biggest days in the Pyrenees but will anyone try and take full control of the overall lead? It would be their last chance in the mountains as the final three stages are a sprint stage, a 30.8km individual time trial, and the Paris stage.
Tim Bonville-Ginn is one of Cycling Weekly's content writers for the web team responsible for writing stories on racing, tech, updating evergreen pages as well as the weekly email newsletter.
Bonville-Ginn started working in cycling journalism while still at school and university for a voluntary site based on Twitter before also doing slots for Eurosport's online web team and has been on location at the Tour de Yorkshire, Tour of Britain, UCI World Championships and various track events. He then joined the Cycling Weekly team in late February of 2020.
When not writing stories for the site, Bonville-Ginn doesn't really switch off his cycling side as he watches every race that is televised as well as being a rider himself and a regular user of the game Pro Cycling Manager.
He rides a Specialized Tarmac SL4 when out on his local roads back in West Yorkshire as well as in northern Hampshire with the hills and mountains being his preferred terrain.
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