A group of cyclists riding on Dartmoor yesterday were stopped and spoken to by police officers after being seen riding at 39mph in a 30mph zone.

While there are no speed limits for cyclists in the UK — except where local byelaws apply, such as in some parks — Devon and Cornwall’s Roads Policing Team explained on Twitter how the group was stopped by officers who asked them to “be mindful of your speeds and just how this will affect you in the event of a collision”.

The traffic unit shared footage of the group descending yesterday morning just after 9:30 on the A386 into a village with a 30mph speed limit for motorists, the video having now been watched almost half a million times in the day since.

On the speedometer visible, the cyclists are shown to be travelling at between 39 and 37mph on the descent.

“Cyclists, please be mindful of your speeds and just how this will effect you in the event of a collision,” the police unit’s post said. “This group today on Dartmoor observed travelling at near 40mph on a 30mph restricted road. All stopped and offered appropriate words of advice.”

The Highway Code sets out speed limits for vehicles, but does not include bicycles,  meaning — byelaw-restricted areas such as some promenades, paths or parks aside — cyclists cannot be fined for speeding.

> Cyclists in Richmond Park face crackdown for ‘speeding’ – even though limits do not apply to them

Instead however, cyclists can be charged with dangerous cycling, under the 1988 Road Traffic Act Section 28, which states an offence is committed if “the way they ride falls far below what would be expected of a competent and careful cyclist” and it “would be obvious to a competent and careful cyclist that riding in that way would be dangerous”, with “dangerous” referring to “danger either of injury to any person or of serious damage to property”.

The charge of ‘wanton and furious cycling’ can also be applied if an injury is caused in the case of a collision.

Predictably, the video has caused much debate on social media, a retired police advanced driver, Marcus Laine, joining the discussion to defend the officers’ actions, saying it was “entirely the right thing to do”.

“Educate and inform,” he said, asking what if “the cyclists approach the restricted vision crossroads and a motorist pulls out expecting traffic to be travelling at 30”?

> Speeding fine for Richmond Park cyclist clocked riding at 41mph — but is penalty lawful?

“It’s about safety and that includes pedestrians who misjudges the bikes speed or elderly drivers. How about some personal responsibility?”

Road safety campaigner CyclingMikey was also on hand to reply to people who suggested the cyclists should be fined as a motorist would be, seemingly not aware of the fact speed limits do not apply to cyclists.

“They weren’t breaking the law,” he said. “The speed limit doesn’t apply to cyclists. That’s probably quite reasonable when a bicycle weighs maybe 10kg and an average car 1.5-2 tonnes.”