Image 1 of 3 Rio Olympic Games cobbles partially paved over (Image credit: Walter Tuche) Image 2 of 3 Rio Olympic Games cobbles partially paved over (Image credit: Walter Tuche) Image 3 of 3 Rio Olympic Games cobbles partially paved over (Image credit: Walter Tuche)

One of the main features of the road cycling circuit for the Summer Olympic Games in Rio de Janiero, the 2km stretch of cobblestone road through the Grumari Nature Park, has been given a strip of tarmac that will be used for the time trial, Cyclingnews learned this week. Some of the worst sections of cobbles for the road race have also been paved over for "rider safety", according to the UCI.

The men and women will contest the time trial on the 24.8km circuit from Pontal - the women race first at 8 a.m. on August 8, taking on one lap for a 29.8km test. The men follow at 10 a.m., and race two laps for a total of 54.5km. Both races will use a smooth strip of tarmac that was recently laid.

The UCI confirmed to Cyclingnews that the cobblestones will still feature in the road races, which use the same circuit in addition to a 25.7km loop around Vista Chinesa and a 22km stretch of flat roads in between the two circuits.

"Road works have been made to allow the Grumari circuit to be used for both the road race and time trial," the UCI head of communications Sébastien Gillot stated. "Short sections of cobbles have been paved to address both rider security for the road race and the needs of the time trial to have a smooth surface. An adjacent lane has been paved along the majority of the cobbles to further enhance the course’s suitable for the time trial.

"Barriers will define the road race course on to the cobbled section, the time trial course will have access to all of the newly paved sections."

The men's road race opens the Olympic cycling events on August 6, with 241.5 total kilometres. After the start at Fort Copacabana, the first 13km are on largely flat roads as riders head to the Grumari circuit, which they take on four times in a row before heading for the Canoas/Vista Chinesa climbs, which they tackle three times with a technical descent at 12.2km to go before the finish back in Fort Copacabana.

The women race two laps of the Grumari circuit and one of the Canoas/Vista Chinesa loop for a total of 141km on August 7.

"The UCI and Rio 2016 are excited about this unique aspect of the road race course that provides almost 2km of challenging cobbles with a stunning backdrop of the South Atlantic Ocean and the environmentally protected area of Grumari," Gillot concluded.