Essentially the same as Wilkie's "Around Glasgow" Route 9, but starting from Partick station instead of Bell's Bridge. He gives mileage as 31 but Cycle.Travel maps it at 34.1 miles.
Mainly NCR (54%) cycle paths - NCR 7 from Partick to Erskine Bridge and NCR 75 from Linwood back to Bell's Bridge. There is around half a mile on rough track at Linwood moss.
There are 4 climbs roughly between mile 7 and mile 15, one of which needs granny gear. Some short undulations from there back to the start.
Good views along the Clyde from Erskine Bridge, and some pleasant quiet rural roads from outside of Bishopton to Linwood.