I only see 54 Cannondale CAAD8 5 Compact Bike - 2015 - REI.com

IDK what you actually got , measure the Bike .. seat tube length is "size"..


BITD the C'dale down tube was the only one welded to the head tube , for small sizes
the top tube lower on the down tube.. Big fat aluminum tubes made it work ..

maybe you wanted the brand and component mix and got that but the smallest size is just large.. For you ..

When you put down 1 foot, lean the bike to one side so it wont be as High..

Company web site : Cannondale Bicycles