This depends on the type of bike you are using.  We do not recommend people use a road bike with thin width tires on the Gravel ride. These are bikes with tires 23-28 mm in width. 

We strongly recommend bikes that have wider tires 35-50 mm in width.  Some bikes, like a mountain bike will have tires that are 2 to 2.5 inches wide, these are fine. This ride will be more a challenging workout for the rider that is in good physical condition.