Puro™ U6 Aluminum Alloy
Our proprietary, ultra light Puro™ U6 aluminum alloy is 25% stronger and 20% more fatigue resistant than traditional 6061-T6 aluminum alloy. We worked with the suppliers of this material to develop custom tubes for our high end frames and forks and we are the only manufacturer using this material for folding bicycle frames. Puro™ U6 aluminum allows us to use thin-wall tubing without sacrificing strength.

6061 Aluminum
6061-T6 aluminum is the workhorse of the bicycling world. It is used to manufacture everything from frames to stems to cranks. It is relatively light, plentiful, and easy to work with. We use 6061 aluminum for several of our frame styles because it can deliver light weight for a reasonable cost.

4130 Chromoly Steel
When it comes to "liveliness" and road feel, steel is still the material of choice for many discerning cyclists. A well-built steel frame can last a lifetime. Almost all steel framed folding bicycles are made from low-cost high-tensile (also called low-carbon) steel. We only use 4130 chromoly steel, which is 40% stronger than high tensile steel. Because of chromoly's significantly higher strength, we can use thinner, and therefore lighter, tubing. 4130 chromoly is why our steel framed bikes feel so "right" and weigh less than many of our competitor's aluminum frame bikes.