Initial prototypes relied on commercially available bicycles
Mass-produced bicycles are typically heavier and have less precise frames.
Therefore, we switched to custom built lightweight frames.
Prototype #1 Twin Cruisers - 2014
(Schwinn Bikes)
First Functional side-by-side flexible twin bicycle.
Prototype #2 Twin City Bikes - 2015
(Gran Royale Step-through)
Custom built frames
Twin City Bikes
Our custom frames are constructed using TIG-welded TIG (Tungsten Inert Gas) welding is a precise welding process that uses a tungsten electrode to create an electric arc that melts the metal and forms a weld. A shielding gas, typically argon, protects the weld area from atmospheric contamination. Filler metal is added to strengthen the joint. 4130 chromium-molybdenum (Cr-Mo) alloy steel tubing.
Cr-Mo is a strong alloy often used in race cars and homebuilt aircraft.
A lightweight design is attained through the use of thin-wall, butted Butting means varying the wall thickness along the tube length to optimize strength where it’s most needed while reducing weight elsewhere. Double-Butted tubes are thicker at both ends to resist localized stresses from welding while the thinner wall center saves weight. and shaped tubes specifically engineered for bicycle frame construction.
Prototype 4 - 2016
Built at United Bicycle Institute (UBI) Frame Building Course in Ashland, Oregon.
Custom built frames
Travel Twin Bicycle
•26” tires, front disk brakes on both operated from left bike.
•Lower step through frame, shorter crank arms.
•Lightweight anodized aluminum tube link bars.
Prototype 6 - 2020
Fast Disassembly
•Quarter turn fasteners – connect link bars to frames.
•Frame Couplings – split frames to fit into travel case.
•Fit each bicycle plus link bars in two 26”x26”x10” airline luggage compliant travel cases.
Custom built frames
700C Road Bicycle
•Ideal for introducing new riders to road cycling, reducing the risk of beginner falls.
•Currently being tested and fine-tuned to ensure top performance.
Prototype 7 Twin Bike - 2024/25