Belkov complained about the incident on Facebook, noting that he "was pushed and kicked out of the bike by one of the 'fans' in a red T-shirt".
He crashed over the barriers and fell into a ditch, saying, "It's outrageous and not athletic in relation to the riders! Maybe someone has a video of what happened."
He later was provided the video below of the incident showing a policeman grabbing the attacker.
Spectator shoved into path of support motorbike in Vuelta a España
A spectator running in the road to cheer on Alberto Contador (Trek-Segafredo) during his attack on the Puerto del Torcal was clipped by a Shimano support motorbike, almost causing the driver to crash.
But another view of the incident appeared to show that the fan was shoved by a policeman into the path of the oncoming vehicle. Luckily the driver was able to avoid a more serious incident.
Gaviria returns to lead Quick-Step Floors at Tour of Britain
The 24-year-old Colombian will lead Quick-Step Floors in the eight-day event, which gets underway in Edinburgh on September 3.
"I'm really happy to return to the Tour of Britain," Gaviria said via a press release. "I had the best experience there two years ago riding as a stagiaire for Quick-Step Floors and immediately winning a stage there with the help of no other than Mark Cavendish. So coming back to Britain now, being part of this great team is a real honour.
"I like this race a lot, and for sure I will try to win a stage. We are present with a strong team and are ready to make a great race out of this!"
With several flat stages on the menu, Gaviria is likely to have multiple stage victory opportunities at the race, and he'll have lead-out man Max Richeze to rely on for the fast finishes.
Dan Martin, Philippe Gilbert and Zdenek Stybar provide the squad with options for the punchier stages or potentially the GC in a race without any major mountains. The Tour of Britain will be Martin's first race back since the Tour de France, where he finished sixth overall.
Quick-Step Floors for the Tour of Britain: Laurens De Plus, Fernando Gaviria, Philippe Gilbert, Daniel Martin, Maximiliano Richeze, Zdenek Stybar