Naturally, as we've seen so many times in the past, if you upload something of interest on the internet, it's not going to go away just because you removed it. In this case, a Liveleak user purportedly downloaded the videos from Michelinman900's channel and shared them with the world.
"A few videos pulled from the guy's YouTube account which he has now removed because it shows the behavior of the group at what I believe is before the incident with the Range Rover," said userMixedWithFruit.
There's roughly an hour's worth of footage in the seven videos, in which the bikers are more of a nuisance, though, sometimes, they do put themselves and other drivers to risk with their actions. For example, they pass red lights on several occasions (4th video at the 1:20 mark and 6th video at 10:00)), they enter opposite lanes, and ride on pedestrian sidewalks (last video at the 1:15 mark).
UPDATE: They've done it before! Skip to 1:15.
I'm looking for more videos.