City commuting specialists Tern have a new group of folders called the 451 Verge family, all based around slightly larger 451mm (effectively 22″) wheels than the typical 20″ wheels (406mm) found on similar bikes. With the new wheels also comes updated geometry to improve stability and overall ride quality, plus the addition of the latest trends in 1x drivetrains. The new Verge X11, Verge P10 & Verge D9- all with the larger wheels – are said to be Tern’s best ever riding bikes to get around and out of town…
Tern wanted to make sure that their new line of folders would be bikes that you wanted to ride everyday, not just something you had to use to get to work & back. So the move to the larger 451mm/22″ wheels was about building a new platform that let them deliver several improvements at the same time. (Just a note: the 451mm rim size is actually also referred to as 20″ x 1 1/4″ or 1 3/8″ by tire makers.)
By going with just a slightly bigger wheel, Tern was able to improve the bike’s gearing, increasing to 102 gear inches, a 10% higher gearing than on regular 20″ wheels with standard drivetrain. That bigger wheel also improves stability, and gave them the opportunity to tune the geometry for an overall improved ride that was less twitchy. That new geometry slightly grows the total wheelbase for better stability, combined with updates to headtube angle and fork rakes.
At the same time the in between 22″ wheel diameter keeps the bike small enough that it still folds into a compact package for easy storage on the train, under your desk at work, or out of the way at home. Building a compact bike is all about compromise, and Tern feels that the new 451 series better hits the sweet spot where you get a better roll-over comfort & momentum with the balance of nimble handling & portability.
The redesign was three years in the making as Tern sought to get a full-size bike feel out of the updated compact folder. The 451 update is also said to fit the bike into almost the same folded size: 38 x 80 x 74 cm (15 x 31.5 x 29.1″). While folded length increases an inch because of the wheel, it actually shrinks back down by being able to use a standard road chainring.
Another improvement for the 451 Verge bikes is the addition of the wide range cassettes of recent 1x groupsets. Now it’s possible to get both higher and lower gearing than ever before with the simplicity of a with a single chainring. Folders have always looked to 1x setups for lower weight, complexity & maintenance, but especially with SRAM cassettes with 10 tooth cogs fast rolling and easy climbing are available in a single folding package.
The top $2500 Verge X11 with a Force 1x setup gets a 420% gear-range (10-42 cassette), as good as most compact doubles. It adds in fast-rolling, paired spoke Kinetix Pro X Disc wheels and Shimano Deore disc brakes to bring you back to a stop, all at just 10.2kg (22.5lb).
For $1400 the Verge P10 shares the same Deore disc brakes and slightly lower cost paired spoke Kinetix Pro Disc wheels, and then gets a Shimano Deore 1×10 drivetrain with a 11-40 cassette. It adds a bit of bulk to weigh in at 11.7kg (25.8lb).
The Verge D9 brings the bigger wheel size down to just $900 with more standard spoked wheels & rim brakes, and a reduced range Shimano Acera 1×9 groupset with an 11-36 cassette. Its weight comes up as well, to 12.2kg (26.9lb), but certainly packs in a lot of folding value.