There is something immediately arresting about the Tetra. Where most folding bikes resolve into a tangle of overlapping tubes, the Seoul-based startup Analog Machine Works has built its design around two opposing tetrahedron shapes — a tubular space-frame that gives the bike a skeletal, almost architectural presence, and one that the company claims enables four distinct fold points rather than the three found on conventional folders.
The South Korean company began developing the Tetra in 2021. Before reaching Kickstarter, the design reportedly won multiple awards for its prototype, though the specific awards have not been independently verified. The crowdfunding campaign launched with a $10,000 goal; as of early July 2026, 24 backers had pledged $52,780 with approximately 21 days remaining.
The folding mechanism — patented by Analog Machine Works as Tetra Fold technology — reduces the bike to 27.5 inches long and 27.5 inches high, with integrated caster wheels allowing the folded package to be rolled rather than carried. Unfolded, the frame extends to 44.9 inches. At 13 kg (28.7 lb), it is not the lightest folder on the market, but Analog Machine Works is not competing on weight.
The more notable engineering choice is at the rear. Where most folding bikes rely on frame flex or simple elastomer blocks for compliance, the Tetra ships with a linkage-based rear suspension system using an adjustable hydraulic shock absorber — a specification more commonly associated with performance mountain or gravel bikes. Whether the shock is proprietary or sourced from a named supplier has not been confirmed by the company.
The component specification is otherwise considered and consistent. The chrome-molybdenum steel frame is paired with 20-inch wheels — larger than the 16-inch wheels used by Brompton and Birdy — shod in Schwalbe Marathon tires. Braking is handled by Shimano disc units; the drivetrain runs a 9-speed Shimano sprocket (11-25T) with an L-TWOO derailleur and a custom 48T crankset. Handlebars are aluminium. The bike is stated to accommodate riders from 5'1
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