Most riders use hybrid style bicycles, with flat handlebars and tyres that are wider than a road bike but narrower than a mountain bike.
It is fine to use a mountain bike or a road bike with dropped handlebars, if that is more comfortable for you.
Some of the rides include sections on gravel or grassy paths.
Mudguards are recommended for the comfort of yourself and others around you.
You can check the details of each ride on Spond.