The world’s best cyclists will be competing in the Tour de France until 26 July. Victory and defeat on the roads of France are decided not only by the riders’ legs, but also by their equipment. The TOUR Tech Briefing for Stage 19.
Final Stage, Part 1: The 19th stage covers just 128 kilometres to Alpe d’Huez. The 21 hairpin bends are a staple of the Tour; the general classification has often been decided here. The route features 3,500 metres of climbing. Given the stage’s short distance, we expect a very fast-paced ride. The official pace chart forecasts averages of 37 to 41 km/h. Judging by how the race has gone so far, the day’s average is likely to be closer to the upper end of that range.
The climb begins straight after the start, which is why the wheels are likely to be whirring in the start area, whilst the riders try to stay as cool as possible. The aim is to bring the leg muscles up to operating temperature whilst keeping the core body temperature as low as possible. This creates a reserve of power for the start of the stage. Those who start with a cool head can rev their ‘engine’ a little higher without overheating straight away. The tricks for doing this include: cooling vests, hand coolers with pumps, fans and much more. Interesting, but not quite taken to its logical conclusion. The day will come when refrigerated lorries are parked at the start of the Tour.
GC riders take on the breakaway
Will any breakaway riders manage to pull away and hold their lead? I expect the UAE team to set a blistering pace right from the start – exactly as fast as Nils Politt can go, which is pretty fast. On another occasion, Politt has already whittled the peloton down to 30 riders. The aim will be to keep the UAE team together for the ride between the mountains. The only conceivable exception: Paul Seixas and Remco Evenepoel launch a daring early attack on the yellow jersey, and the battle amongst the GC contenders flares up at kilometre one. An enticing thought, but unfortunately also a very unlikely one.
The reality is this: anyone wanting to break away will have to go all out on the very first climb and give it their all to shake off Politt and the rest. And then they’ll have to hold on through the long descent between the mountains.
The classic climb to Alpe d’Huez is so prestigious that Tadej Pogacar will likely want to win here in the yellow jersey in front of a huge crowd and extend his lead. As he also has the strongest team in the Tour, he is in a better position than anyone else in the field to put his plan into action.
If any breakaway riders manage to get away, they will therefore almost certainly not be given free rein, but will be kept on a long leash with a sense of proportion, so that Pogacar can overtake them as planned in the final stretch.
That’s the script, if everything goes to plan. Fortunately, there are all sorts of uncertainties, so we’re still left with a sense of suspense.
Technique for the final climb
Today’s technical analysis focuses on the final climb. What adjustments can be made to minimise the riding time? Does drafting still play a role once the first hairpin bend has been taken?
To investigate this, we’re running various scenarios through the computer. At the same time, we’re looking into whether Tadej Pogacar could break the existing records on this climb and what role his bike would play in that.
Marco Pantani’s official course record stands at 37 minutes and 35 seconds, set in 1997 – albeit over a longer measured distance of 14.5 kilometres at the time. Converted to today’s standard distance of 13.8 kilometres, this gives an unofficial time of 36:55 minutes. Pantani was even faster two years earlier: in 1995, he clocked 36:50 minutes over the same converted distance – a time that remains the undisputed best to this day.
That was a legendary time that has never been matched since, not even in time trials, even though Pantani set that time at the end of a gruelling stage.
Is it possible to achieve a better time using modern cycling technology and today’s knowledge, without EPO?
According to our calculations: yes. The record could theoretically be broken if Tadej Pogacar were to tackle the climb at maximum speed right from the start. The fastest calculated time, based on an average power output of 440 watts and the optimal bike setup, is 35:59 minutes (6.7 W/kg). That would be a new record.
In modern cycling, however, such epic attacks are rather rare. If the battle for victory only really gets underway in the second half – or even later – the record is unlikely to be broken.
The speed on the climb ranges between 17 and 26 km/h, whilst speeds in excess of 30 km/h are also achieved on the flatter upper section. Aerodynamics is therefore a minor, but not insignificant, factor. This is also evident from the calculated differences in ride time between the Colnago Y1RS – which Pogacar rides as standard – and the lightweight V5RS: the less aerodynamic lightweight bike would be 7 seconds slower, assuming the same weight.
However, the lightweight bike beats the more modern Y1RS by two seconds, even if it is 400 grams heavier.
At typical climbing speeds, the slipstream plays only a minor role, but it is noticeable – especially on the flatter sections.
The Alpe d’Huez formula: 400 grams = 9 seconds
We suspect that the mechanics will do their utmost to get the aerodynamic Colnago Y1RS down to 6.8 kilograms. If it were to weigh 7.2 instead of the minimum permitted 6.8 kilograms, Pogacar would lose 9 seconds on the road and would actually be two seconds faster with his old V5RS at the minimum weight.
Possible bikes ridden by the favourite in the time trial:
The bike of the presumed winner in various configurations: the Colnago Y1RS in five weight categories ranging from 6.8 to 7.2 kg. As the table shows, the lightweight V5RS sneaks ahead of the aero bikes in the rankings when it is 400 g above the minimum weight (as was the case when it was weighed during this tour).
The last two lines show what happens if the drive’s efficiency is lower (+9 seconds due to poorer lubrication on the chain) or the tyre rolls less efficiently (+10 seconds).
After all, both effects are more noticeable than the 400-gram difference in weight!
An amateur cyclist (78 kg, 240 W FTP) for comparison – using Pogacar’s kit:
With professional-grade equipment, a typical amateur cyclist could achieve a time of around 1 minute 12 seconds at 3 W/kg – if they gave it their all. FTP is usually an optimistic estimate for an hour; here, the calculated ride time is already longer than an hour.
* Simulation calculations
Based on our own wind tunnel tests, we carry out simulation calculations for the Tour de France tech briefing. How TOUR tests: Aero road bike test in the wind tunnel.
We are investigating which wheels can offer a technical advantage in which situations. The variables we can control in the simulation include wheel weight, rider weight, the inertia of the wheels, the drag coefficient, the rolling resistance coefficient and the efficiency of the drivetrain.
To model ride times, we use realistic power outputs and weights for the riders, combine these with our wind tunnel data, and have the riders race virtually along selected sections of the route, which we extract from the official route data; the derived elevation profiles are key to this. The modelling also includes bends, which we can brake for realistically, and adjustable power profiles for different types of riders. This allows us to distinguish between hill climbs and proper final sprints. Taken together, this makes the simulation very realistic. What we cannot replicate are dynamic handling effects such as the individual behaviour of the wheels on different surfaces.
The journey times calculated for the sections of the route that are decisive for the race highlight the influence of the wheels – provided that the riders always behave in the same way in a given scenario.
Robert Kühnen
Editor