The motorcycles were travelling southbound on Highway 99 at Porteau Road in Squamish around 9 p.m. PT Thursday, police said.
They were first seen traveling at an estimated speed of 140 km/h, then increased their speed after passing a police officer.
"Since all six motorcycles were travelling within two to three metres of each other, we stopped the entire group," RCMP Cpl. Robert McDonald said.
"Each rider received an excessive speed violation ticket under the Motor Vehicle Act, and in accordance with that act, each motorcycle was automatically seized for a seven-day impound."
The drivers, who were riding Honda, Ducati and Aprilia motorbikes, were each fined $483.
"I would definitely categorize this as extreme speed, at more than double the limit. Their actions were even more dangerous because they were all two to three metres from each other," McDonald said.
"Getting pulled over may have been the best thing that ever happened to them."
Yesterday, RCMP released a video of a speeding motorcyclist who was so preoccupied with his speedometer, he slammed into a young, black bear crossing Highway 7 in the Fraser Valley.