The Vuelta a San Juan heads into the Andes on Friday for the only mountain finish of the race, with the 2,565-metre high climb expected to shake up the overall classification with only two flat stages left to race.
Julian Alaphilippe (Deceuninck-QuickStep) will wear the leader's white jersey during the 169.5km stage after winning stage 2 on the edge of the Punta Negra dam and the 12km stage 3 time trial. The Frenchman leads Fernando Gaviria (UAE Team Emirates) by eight seconds overall, with his teammate Valerio Conti third at 22 seconds.
Gaviria has admitted that he is focused on stage victories, and so Conti will lead UAE Team Emirates' hopes. However, the overall classification remains open with 10 riders within a minute of race leadership. These include Nairo Quintana, who is eighth at 48 seconds, while his Movistar teammate Richard Carapaz is 11th at 1:04.
Felix Großschartner (Bora-Hansgrohe) is better known for his time trialling, but the 64kg Austrian could remain an overall contender. He's sixth overall after a strong time trial, just 26 seconds down on Alaphilippe.
Deceuninck-QuickStep also have Remco Evenepoel in fourth place at 22 seconds. Until the IIjo Keisse case exploded, the 19-year-old neo-pro was the emerging story of the 2019 Vuelta a San Juan. If Evenepoel can finish on the podium, or even win, it will be a historic debut at WorldTour level, only sparking more comparisons with Eddy Merckx.
Last year, the Alto Colorado finish saw then Argentinean national champion Gonzalo Najar of the local SEP de San Juan team win alone after an audacious solo attack with 20km to race. He celebrated by waving his arms in a celebration not too dissimilar to those of former pro Alberto Condor, but Najar's Icarus-like wings were clipped a few months later when the UCI revealed that he had tested positive for CERA, and he was disqualified. Oscar Sevilla finished second to Najar on Alto Colorado and gained enough time on his rivals to win overall.
Breathtakingly high but not steep
Alto Colorado is breathtakingly high at 2,565 metres, limiting oxygen take-up at the summit, but the gradient of the final 15km is listed as only 4.4 per cent in the race manual.
Last year, Italian track pursuit and cobbled Classics specialist Filippo Ganna led the Vuelta a San Juan after the time trial and only lost 25 seconds to Sevilla in the final kilometres. Weather forecasts indicate that there'll be a tailwind on the climb on Friday, and so that will limit the time attacks – and especially solo attacks – can gain.
That could help Alaphilippe and blunt possible attacks from climbers such as Quintana and local riders such as Ricardo Escuela and his ACA Virgen de Fatima teammate German Tivani. Of course, other riders will be looking for a simple stage victory, and so could try to blow the race apart early on the climb, as Najar did last year.
The 169km stage includes two time-bonus sprints at 30.6km and 87.8km. Earlier climbs to help any breaks come after 63.4km into the day, 107.1km and 121.8km.
Quintana and Alaphilippe motivated
"Tomorrow is a long climb, but it's not too hard," Quintana confirmed, hinting he would ride aggressively, as he had when Alaphilippe went on to win stage 2.
"A lot of people can finish together. We're well placed and, as ever, we'll be vigilant and try to do something.
"I feel good and I'm on good form," Quintana continued. "I'm not 100 per cent, because it's my first race, but I've trained hard recently."
Alaphilippe said he and Deceuninck-QuickStep would take things day by day. He has kept a low profile since the Keisse scandal exploded, but went training for two hours on the rest day.
Deceuninck-QuickStep have brought a lightweight Specialized Tarmac bike for the mountain stage in a clear sign of their intentions.
"I'm motivated to race full gas," Alaphilippe said.
"Alto Colorado will be really important for the GC. It'll be a really hard stage, but if I feel good and continue to keep the jersey afterwards, I'll be really, really happy. If I lose it, I'll still be really happy with my race."
Cyclingnews will have full live coverage of the stage followed by a full stage report, results and a photo gallery, and news and interviews from the race.