Flying Eagle F4 Raven Skates. The F4 Raven holds up to all it has been claimed. It is perhaps the best valued urban skate we've come across. It is incredibly comfortable, easy to get in and out of and loaded with features at an amazingly low price. up to all its claims, being perhaps the best valued urban skate we've come across. CNC machined aluminum frames (removable and laterally adjustable - mount 165mm, 180mm or 195mm) with 85A wheels (size depends on skate size) and ABEC7 bearings.