A friend of mine runs a group called Prestwich pootlers. They do a couple of tours a year, normally a variation on coast to coast over 3 or 4 days. Pace is leisurely.
There is also a face book based group Manchester social cycling that normally do a couple of rides a month, one of them is normally an intro ride for people that have not done group riding before. Pace is normally around 12-14mph but they ride at the pace of the slowest rider, nobody is left behind. Their rides normally leave from the velodrome and go out to Cheshire, or North towards Hollingworth lake/Hebdon Bridge.