The Cape Cod Canal is edged by level, well-maintained service roads perfect for biking. The mainland side has almost 7 miles of trail; the Cape side has 6.5 miles.
Access points along the mainland side of the canal include Scusset State Park off Scusset Beach Road; the Sagamore Recreation Area off Canal Road at the Sagamore Bridge; near the Bournedale Herring Run in Bournedale; and beneath the Bourne Bridge. On the Cape side of the canal, there are access points from the Sandcatcher Recreation Area off Tupper Road in Sandwich; from Pleasant Street in Sagamore; and from the Bourne Bridge.
If you want to cross the canal with your bike, use the Sagamore Bridge—its sidewalk is safer.
Bike Rentals => Sailworld Cape Cod (see web page noted above).