In reply to Pietrach:
Out & back along the canal west to Bowling or Balloch
Out & back along the canal east to Auchinstarry or wherever.
Get the train to Paisley Canal and then cycle route to Lochwinnoch for ice cream, cycle track continues to Kilbirnie. Only a short section on roads.
Train to Drumfrochar (avoids a lot of the climb out of Greenock but check if the steep gradient/traffic is suitable), up (very steep) to Papermill Road, Greenock Cut (flat) & direct return (a steep bit) from Ardgowan Fishery Cafe.
Post edited at 11:19