I'm torn with this one, but I have to say, that even though I used my folding bicycle in Nassau (harrowing experience, by the way) and on Great Exuma, it is truly a pain in the you-know-what to keep on the boat, transport in the dink, and also to keep lubricated.  Just in the few weeks that it has been riding on the boat since Nassau, I had to use a can of WD40 to un-stick the gearing, brakes, and joints as they had already seized from the corrosion.  Okay, granted, I only paid 50-bucks for the thing at Sailorman (used) but it is a marine bike and I only used it a few weeks ago.  You can rent a bike in Nassau as well as Great Exuma.  The other islands were either not big enough or had no terrain on which to bike, so keep the rust off your cabin top, open up some space on your boat and forget about taking the bike.