There is so much to explore by bike near Montreal. Instead of taking Lachine along to Old Montreal, you can go the opposite direction, along Boulevard St. Joseph. There are parts that have not been marked very well, but it is a fun little bike ride and it is not as busy. It is still a bike path, but note, there are walkers and runners, so share the road.
Off we went, picnic in bakfiets, and ready to feed the ducks. This Map is courtesy of MuseesMontreal:
The bakfiets ready for the long haul!
There are a few lighthouses and picnic areas to stop at. There are also no public washrooms anywhere on this route outside of peak season, so be prepared to stop at a restaurant, or maybe a wonderful museum for an hour or two!