Tern BYB S11 review

New Ultegra-equipped slimline folder

Our rating 
4.0 out of 5 star rating 4.0
GBP £2,300.00 RRP | USD $2,499.00 | AUD $3,870.00

Our review

If you’re after ride quality, it’s one of the best handling folders around
Pros: Solid handling, stable ride, great gear range
Cons: Pricey, heavy and folding is more time consuming than simpler designs (and the Brompton)
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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.

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.

Shimano gears and brake levers
Shimano gearing makes for smooth shifting
Robert Smith

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.

FSA Gossamer Pro chainset with 54t Megatooth chainring
FSA Gossamer Pro chainset with 54t Megatooth chainring
Robert Smith

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.

Tern BYB S11 01
Tern’s new Ultegra-equipped slimline folder
Robert Smith

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.

Product Specifications


Price AUD $3870.00GBP £2300.00USD $2499.00
Weight 13.3kg – inc. pedals
Brand Tern


Brakes Tektro V brakes/Shimano R780 levers
Chain Shimano
Cranks FSA Gossamer Pro with 54t Megatooth chainring
Fork Aluminium
Frame Aluminium
Handlebar Kinetix
Rear derailleur Shimano Ultegra
Saddle Ergon
Seatpost Tern telescopic alloy
Shifter Shimano RS700 shifter pod
Wheels Kinetix Pro