Titanium is used in aircraft engines and medical devices, and is also an ideal material for folding bikes because of its strength, high wear resistance and rust-proof properties. We use Ti-3Al-2.5V titanium tubings for our frames. The frames do not need painting and still look awesome. 

While the folding designs themselves are novel, we have adopted a minimalist approach to their implementation by using as few joints as possible to achieve the desired functions. The joints are based on tried and tested single-axis pivot hinge design, for reliability and ease of manufacture. They are made of titanium with replaceable bronze bushings.  

No, it does not. In fact, by design our main frame hinge is oversized and over-built to be stiffer and stronger than the frame tubing. It adds a little more weight to the frame, but does not sacrifice structural integrity.

The type of hinge joint is also an important consideration. The single degree-of-freedom revolute joint used in the main frame is a tried-and-tested design proven in the industry to be robust and long lasting. 

Some folding bike designs boast a "hinge-free" main frame. Instead they have a hinge on the front fork to achieve a compact fold. For reasons of safety and durability, we don't prefer this solution as the front fork bears a much greater stress when riding over bumps and braking. Further, any looseness in the joint that develops with use over time will affect the steering precision and stability of the bike.

The Burke 20 and the Burke 16 are compatible with a wide selection of internal gear hubs and rear derailleur gears, including SRAM and Shimano gears. The Burke 8 is a single speed, designed to be one of the most fuss-free, most compact and lightest adult bikes on the market. 

For the same pedaling torque and cadence (crank rotation speed), smaller 16" and 20" wheels are just as fast as  700C or 26" wheels, provided that, (i) higher gearing is available, and (ii) good quality, high pressure tires with low rolling resistance are used. Small wheels could also be made lighter and have lower wind resistance, thus allowing for faster acceleration than bigger wheels.

The stability of a bike is not determined by the diameter of its wheels. A well-designed small wheel bike is as stable and easy to ride as a big wheel bike. Consider, for example, the city scooter and the commuter motorcycle. Both have wheels of diameter around 16 inches and obviously are stable enough to move at a high speed.

You don't need big wheels to make a bike self-stable. Here is the latest research report on this topic.

Bikes with smaller wheels can be designed to be more responsive and maneuverable, an advantage for navigating busy city streets.

We offer different models for different applications, depending on the desired performance of the bikes. Generally, the smaller the wheels, the shorter the bike, thus making it easier to roll into elevators or trains unfolded, and less intimidating to other users on pavements, footpaths, and crowded spaces. They also allow for a more compact fold. However, we also need to consider the availability of tires, rims and gearing options. For example, the 20-inch (ISO 406) wheel size is the most common wheel size after 700C and 26-inch (ISO 559), and offers a great selection of high quality rims and tires. It also allows for a greater combination of chainrings, hub and derailleur gears.

The bikes will be hand-built in the USA. We are currently working with a few bike builders in the Pacific Northwest to start production in 2016. We are also open to the possibility of licensed production of our designs by other manufacturers. Please contact us for discussion.

The bikes will be launched officially at Interbike 2015 in September. Manufacturers, distributors, and dealers could also visit our showroom in Seattle for test rides and demonstration. Please contact us for details.

Production is scheduled to start in mid-2016. The bikes will first be available for order at selected bike shops in the US around the first or second quarter of 2017. We welcome local and overseas dealer inquiry.