A folding bike can be tucked up in about 30 seconds, then placed in a car’s trunk, toted on a train, stashed on a boat, or stuck in a suitcase and checked on a plane (conventional bikes cost up to $100 to check and need a special box). Folding bikes have smaller wheels than regular bikes, but their gearing enables some to be ridden as fast.

What we tested. We bought five folding bikes from major makers (they’re sold at independent dealers or online) and put them through tests similar to those we use for regular bikes. Four of the folding bikes have seven or eight gears that you shift by twisting the grip. The Brompton has three gears and a trigger shifter. All the bikes have seat posts adjustable for riders of very different sizes, and the tested Bike Friday has three frame sizes (the company also produces custom-made bikes).

What we found. Our first discovery was that convenience costs: Although most of the tested bikes are at the low end of the manufacturer’s line, prices ranged from $380 to $830.

Next, we found that performance doesn’t follow price. Although all bikes were at least good overall, all shifted very well, and all braked within 15 feet when going 15 mph, none stood out across the board. The Ratings provide details.

How to choose. A folding bike could be useful for commuters or for travelers who want to combine cycling with sightseeing but can’t rent a bike where they’re going. First make sure that the bike is comfortable. As you’re riding, there should be a very slight bend in your knee when the ball of your foot is on the pedal at its lowest position. Then check that the bike will suit your situation: