The frame is the heart of the bicycle's integrity. It is the most important part that determines the performance and safety of the bike. A lot of engineering and material science go into designing a frame that is strong, rigid and lightweight. These are contrary engineering objectives: a rigid frame can be brittle and easily crack, a steel frame can be strong, but heavy. Typically, as the strength to weight ratio of a frame increases, the cost increases exponentially. Rigidity or stiffness of the frame determines the efficiency in transferring a rider’s energy in pedaling into propelling the bike forward : otherwise the force applied to pedaling will be wasted by flexing the frame from side to side. The more rigid the frame, the more responsive and faster the bike since the energy of pedaling will transfer power directly to turning the wheel. ZiZZO is quite an engineering feat considering when the frame unfolds and locks together it becomes more rigid than most traditional bikes, comparable to the expensive mountain and road bikes costing thousands of dollars. The aluminum alloy frame gives it the best strength to weight ratio at an affordable cost. Typically when people consider a folding bike, they think under-performance, slow, unstable and hard to pedal. ZiZZO's goal is not to develop a “folding bike” but an all-around performance bike that folds. Due to our strong, rigid and light frame design, people all over are amazed at how well ZiZZO bikes perform. They are fun to ride: fast, quick, easy and safe.
Gearing or gears and gear inches are the great equalizers in cycling. They can turn a small 20 inch wheeled bike into a world record speed machine as in the case of Bluenose when in 2013 at 83.13 MPH set the world speed record for a bike. What it all boils down to is designing front and rear gear sizes that will provide the correct gear inches or the distance you move per revolution of the crank arm. In the case of typical mountain bikes, gear inches range from 25” in your lowest gear to 87” in your high gear (Trek 820). In the case of your average road bike, the range is 28” in your low to 120” in your highest gear (Diamondback Century). In the case of the ZiZZO, the bike was designed for an “all around” ride and we chose a range from 30” in the lowest gear to 87” in the highest gear. What all these numbers mean is this: ZiZZO is designed to ride as easily up a hill as your typical road bike and as fast as an average mountain bike.
Quick Acceleration: As mentioned in "Gear Inches" above, 20 inch wheeled bikes can ride fast like the record setting Bluenose. They are quicker accelerating, because 20 inch wheels are lighter and have less mass; therefore they have less moment of inertia. In stop and go riding, the quicker acceleration of a smaller wheel translates to a more efficient ride.
More agile: Like their BMX counterpart, 20 inch Small wheels create a more maneuverable bike. Because of their size, they are more responsive to steering and they present increased tire compliance with the road surface because they get higher pressure per square inch on the ground. The superior maneuverability is particularly helpful on wet surfaces and in tight turns. In addition, the overall compact size with wide tires makes the bike sturdier and more comfortable.
Strength: 20” wheels are inherently stronger than their larger counter parts. Shorter spokes mean stronger wheels. Because a 20-inch wheel has a smaller circumference than a larger 26-29” wheel, the rim is structurally stronger and resists deformation from impact.
Fit: Easier to fit a wider range of riders. The larger wheels require bigger bike frame geometry overall, making 26”, 27.5” and 29” wheel equipped bikes more suitable for bigger or taller riders. Whereas ZiZZO can fit male and female from 4’8” to 6’3"
Size and weight: Because ZiZZO is a bike that folds, it smartly takes advantage of a smaller wheel’s portability and lighter weight.The only drawback of smaller wheels is that they do not negotiate over obstacles as well. This is typically a non-issue since most bike ridings are on a pave or dirt road. Plus, the ZiZZO's wide tires add dampening to compensate for the smaller wheels.
Stack, reach, and the two angles (headtube and seat tube) are the main ways that a traditional bike is measured. These are important measurements for bikes that determine just how comfortable and agile a bike will ride. As the diagram shows, the wheel base, and both the headtube and seat tube angles are comparable to a typical mountain bike. When looking at bike sizes, the measurement that changes is the stack and reach. ZiZZO bikes uniquely get around problems with sizing frames by making the seat post adjustable (thereby being able to change the stack height) and designing the stem to be adjustable (changing the reach). Being able to adjust these two lengths allows riders of differing heights to ride the same bike while maintaining similar angles and wheelbase as traditional bikes.
Rider comfort comes from where your body interfaces with the bike. That’s the handlebar and seat. We talked about how the ZiZZO frame is more rigid than most traditional frames. Rigidity, as discussed can make a rider more efficient, transferring pedaling energy into powering the bike forward, but it can fatigue a rider as well when the stiffness of the bike transfers all the shocks from bumps and holes of the road directly to the rider's arms and back. To overcome the challenge of providing comfort for a stiff frame, ZiZZO bikes are designed to flex at the seat post and handlebar stem. This provides the comfort to the rider, mile after mile of biking. In other words, the ZiZZO is rigid and efficient where it needs to be, but supple and comfortable where you want it to be. Fit solutions are just one advantage of ZiZZO bikes. Because of their adjustability, you can change rider position to your preferred riding style, from an upright casual ride to a lower profile commute on the go.
ZiZZO bikes have been rigorously tested for strength and stiffness. We've tested our bikes using three standard tests: Lateral Bending Stiffness, Tire Contact Lateral Bending Stiffness, and Front Triangle Stiffness. Independent testing company, Bike Testing, Inc. in the USA has proven that the ZiZZO has an overall stiffness rating comparable to traditional bikes costing thousands! That’s right, our bikes performed as well, if not better than some professional bikes but at a fraction of their price!
The frame is positioned horizontally on the test-bed and the head tube is clamped securely and rigidly to the head tube test-bed fixture. The bottom bracket shell rests firmly on the test bed and is simply supported at a height, which positions the frame in the horizontal plane. A solid dummy rear axle is clamped into the rear fork-ends (in the case of adjustable type rear fork ends the dummy rear axle is positioned such as to make the wheelbase as short as possible). Deflection measurements are taken from the top of the dummy rear axle with a 0.001-inch dial indicator. Weights are hung from the bottom of the dummy rear axle and measurements are taken with four different pre-loads, each time measuring the deflection caused by adding a 3.0-pound weight.
The frame is positioned horizontally and clamped at the head tube bearings. The bearings are held rigidly so that the frame can rotate about the bearings. A bar is installed into the BB which clamps onto the BB shell and positions the BB 1 1/2" from a stand which the bar rests on. The bar has a rounded end on it to allow the BB to rotate on the stand. Oil is placed on the stand at the contact point to further allow movement. An axle is bolted into the rear dropouts which have a bar attached to it 90 degrees from the plane of the axle. The axle/ bar represent the rear wheel. The bar extending from the axle is placed into position so that the bar intersects the point at which the wheel makes contact with the ground. Weights are placed onto the contact point and deflection is measured to determine stiffness.
The frame is positioned horizontally on the test-bed and the head tube is clamped securely and rigidly to the head tube test-bed fixture. The torsion-testing lever is bolted rigidly into the bottom bracket shell and projects horizontally in the opposite direction of the seat tube. While the bottom bracket shell rests firmly on the elevated portion of the test bed it is otherwise unrestrained. During the measurement the frame has no additional equipment mounted on it nor is it restrained in any other way. Deflection measurements are made by applying torque to the bottom bracket shell by means of the torsion-testing lever (which is pre-marked at 30.5 inches from the center of the bottom bracket shell). The angular deflection of the bottom bracket shell is measured by measuring the total angular deflection of the torsion-testing lever and subtracting the deflection that occurs in the torsion-testing lever itself. The resultant bottom bracket torsion rigidity is calculated as torque expressed in ft-lbs, divided by the angular deflection in degrees.