A folding bike lets you combine a train's town-to-town speed with the across-town efficiency of the bicycle. Ride to the station, fold the bike, board the train, stash the bike in a luggage rack, then alight, unfold, and ride those last few miles at the other end. It's seamless. Taking a full-size bike on a train, by contrast, is process riddled with awkwardness and uncertainty. If you're doing it daily, you want a folder – and not just any folder: a compact folder.
What defines a compact folder? The bike must be 'fully folding' and have 'wheels up to 20 inches in diameter'. A folding bike with bigger wheels can be refused by the guard or else treated as a full-size bike – with all the restrictions that brings.
Any compact folding bike that rides well and is easy to carry will be relatively expensive. Expect to spend at least €500, and twice that for a benchmark folder like the Brompton. Cheap folders tend to handle poorly, due flex in the frame or stem hinges or to poor steering geometry. They're often very heavy too – and you don't want to haul a 14kg tangle of metal over a footbridge on a regular basis.
The easier and quicker it is to fold the bike, the better. You'll be doing those hinges several times a day, possibly when a train is seconds from departing. Once folded, it's much more convenient if the bike stands up by itself and doesn't swing open whenever you pick it up. Unfolded, the hinges should fasten securely and flex-free, and the contact points (handlebar, saddle) should go where you want them. Compact folders are usually one-size-fits-all, which can be an issue for tall riders.
Small wheels save space but do have drawbacks. Steering is sharper, so you need to take more care when you remove one hand from the handlebar to signal. Potholes and bumps are a proportionately bigger problem. While smaller wheels are also slightly slower than bigger ones, this difference can be offset by using good quality tyres that are properly inflated.
Like town bikes, compact folders are generally ridden shortish distances in normal clothes. Mudguards are thus more important than lots of gears. Six to eights gears is plenty even in hilly areas, and for flatter trips three, two or even one gear is sufficient. With fewer gears, a folder can be lighter and thus easier to carry, as well as mechanically more robust. Brakes, meanwhile, require a bit more care. The cable runs tend to be convoluted, which adds friction and decreases braking effectiveness over time.
Compact folders are limited when it comes to luggage: pannier use is constrained by ground and heel clearance. A rear rack is nevertheless useful for a trunk bag, and some folders will carry a larger bag over the front wheel. Lights and other permanent accessories should ideally remain in place during folding; it saves time and reduces the risk of breakage.
One extra you may not need is a lock. A compact folder can go indoors with you, parking underneath a desk or coat rack.
Here are two compact folders at different price points.
Giant Halfway City
Giant’s 20-inch wheel bike folds in half around a central hinge, with the seat post and stem dropping down. That’s like the Tern Link and many other folders. What’s different about the Halfway is that the wheels are supported on one side only. This looks odd but is structurally sound, and it makes it easier to fix punctures as the wheels can stay in place. The Halfway is a similar weight and size (approx 79x76x34cm) to the Link C7, which is compact enough for National Rail, and it too has a 7-speed derailleur. It comes with mudguards, a kickstand, and a rear rack that’s high enough that small ‘front’ panniers might be used.
The Brompton is the most compact, genuinely rideable folding bike. That’s why you see so many at station concourses. It packs down to 58.5x54.5x27cm, small enough to slide between intercity seat backs. The fold is clever. You flip the rear wheel under, undo the frame hinge and fold the front end back, drop the handlebar down, then lower the seatpost. It takes about 15 seconds. Bike handling is ‘nippy’ due to the small, 16-inch wheels, but you quickly get used to it. There are endless Brompton configurations and accessories. For commuting, this 11.4kg S3L 3-speed with mudguards and a flat handlebar is ideal. Budget for lighting if you can, and plan to buy the excellent front luggage system.
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