Complex sentence: Greebos usually went to the many motorcycle rallies around the UK and indeed Europe, many of which are still going and the original Greebos still attend even though many are in their 50s and 60s.
Split into simpler sentences: Greebos usually went to the many motorcycle rallies around the UK and indeed Europe, many of which are still going. Indeed, original Greebos still attend, even though many are in their 50s and 60s.