The design of various types of bicycles has improved in the past century and is generally considered to be optimized based on ergonomics and physics. Folding bicycles are bicycles, so traditional techniques must be followed, and the interaction between the cyclist and the road must be considered.
The main parameters of the bicycle are: wheelbase, frame height and angle, front fork angle and offset, handlebar position, strength, rigidity, etc. Each parameter will be slightly changed according to the size and purpose of the car, otherwise the performance will be affected. No matter what kind of bicycle, the strength of the frame and handlebar system is very important to the safety of the cyclist. This is widely recognized. However, few people realize that the rigidity of the folding bicycle frame and handlebar system is equally important. For efficiency and maneuverability, it may ultimately be for safety.
The most important rigidity requirement of a bicycle is the rigidity between the bottom brackets. This needs to be determined based on the stiffness between the bottom bracket and the handlebar. The stiffness of the frame riser is relatively secondary, which is more important for folding bicycle for sale. The entire frame and handlebar system must be horizontal, twistable and vertical. When the bicycle is swaying from side to side regularly, the pedaling remains stable. Up to 20% of the pedaling force is converted to the lateral vector. In difficult riding, a small but still part of the force acts on the handlebars. The extra flexibility of the frame and handlebar system during pedaling comes at the expense of forward propulsion.
For the lightest folding electric bicycles, the longer handlebar system must be strong and stable. This also applies to the frame seat tube. Again, this is necessary for good riding and ergonomics and safety, especially for taller and heavier riders.