Tern BYB S11 review

Tern’s ‘smallest-ever’ folding bike is no threat to the Brompton – it might pack down small, but not that tiny at 81cm tall, 35cm wide and 52cm deep. With the Metro Transit rear rack and its integrated trolley wheels, it’s easy to move though, even at 13.3kg.

• Tern launches its smallest folder yet
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You can completely fold the bike down, including the long stem-cum-steerer (or ‘Physis’ handlepost), or leave the bar extended to help manoeuvre when trolleying. The tri-fold system requires unclipping the joints, removing one of the quick-release MKS pedals and hoisting the pedal on to the frame holster. Then fold the bike up and press the anchor bolt (mounted on to the fork) into the rear dropout. It’s a more secure set-up than Tern’s old magnetic clasp, though unlocking involves activating a lever mounted on the rear-stay. This can be messy to reach, especially after riding in poor weather, although usefully a PopCover mounted on to the rear rack can create a shelter for the folded bike.

Overall, the ride is where the BYB scores. The long wheelbase, 20-inch wheels and twin-spar frame design add solidity, banishing the noodly feel of similar folders. Up front, the Physis steerer and Andros stem combo is suitably stiff, too, so this is one of the few folding bikes I’m happy to get out of the saddle and sprint on. On paper, the dual quick-release bar clamp/stem angle adjustment on the Andros looked a faff, but it means you can tune the reach, bar angle and stack easily, resulting in your optimum position. The telescopic seatpost also guarantees your perfect saddle height.

The BYB’s 20-inch wheels with 1.5in tyres provide swift acceleration, and led to several excursions off-road. The gear range is a bonus. An 11-speed, 11-32 cassette driven by an Ultegra mech and a 54-tooth chainring offers a decent range. The low climbing gear’s complemented by a top end that’s enough to keep you ahead of traffic. That range of gears is something you don’t get from many of BYB’s rivals, forging a ride that’s comparable to a ‘proper’ bike, not compromised by its compact folding design.

The Tern handles quickly without being twitchy and with the solidity of its chassis you have a decent mixed-mode commuter bike. It is expensive, but it has broader gearing and superior handling and is easier riding over longer distances. Aiming it at commuters rather than tourers or general riders, at £2300 / US$2,499 / AU$3,870, may be a tough sell.