Lattice forged hinge those in the know understand that a folding bicycles success lies mainly with its hinge dahon have devoted years of rnd to refining our lattice forged hinge the end result is feather light but a heavyweight in strength and performance dahon achieves this through cold forging and cnc tooling including stainless steel and brass components to stand up to all weathers and wear and tear shimano 3 speed drivetrain a shimano 3 speed drivetrain is what powers the curvenb