Here is an interesting compilation (work in progress) on how to carry your bike to and from the ride if you do not cycle all the route !
https://docs.google.com/document/d/1n4aFcC8RyvZgPJyUUc15Pi2SCKG7kEcwSDHQi0W-a48/edit?usp=sharing
Note: consider renting a bike if you want to join on a short period and the raid is far from your hometown!