Is speed of scheduled group rides always slower than other riders in 'free ride' mode?

I was having a jolly last night, and came upon a large group and I had no trouble overtaking the group. This appeared to be an organised group ride…but all of them had w/kg that were quite a bit higher than mine (~4w/kg vs ~3w/kg). I thought that speed in the game was determined by w/kg, so how come I was overtaking them? Is the in-game speed of groups that other riders see/experience, who didn’t join,  much lower than that of other riders? And is this to dis-encourage non-joiners to join/tag along with group rides? Is it something completely different?

I Bet it was Group workout ride (Noob Train) mode limit speed.


That was more than likely a group workout, where speed is controlled as a group, despite different levels of intensity.