Well I've actually been able to do that only a few times, because the group only consists of about 10 riders usually, and we're all in a tight two-man paceline. So really I've never found an easy way to stay at the back without falling off the pack. And I am accompanied by one or two other people sometimes who do the same, the group doesn't mind because they know I'm a young newbie that's just trying to stay with the group for the ride. ..Also, the riders are all really fast and can hold 45+ for about 60-70 km on our Tuesday rides, so the gaps I leave on our 'slower' Thursday rides, it's not a problem for them.