The $579.95 Dahon Helios is the lightest bike in our test group and has the smallest folded dimensions.

Not so long ago, if you wanted to bring a bike along cruising, you had to partially disassemble it to fit below, then try to reassemble the ball of rust when you were ready to use it again.

Fortunately, manufacturers have been refining their wares for the last 20 years and now offer bikes constructed of more sea-friendly materials with folding systems that allow easier stowage, without affecting the frame’s rigidity too much.

We evaluated four models, all under $700. We paid close attention to the materials used, the strength and efficiency of the folding system, and portability with respect to the limited storage space in cruising powerboats. Ergonomics and performance…