The concept is the use of better structure and change handle place to reduce the hardness of riding on and the high weight of the folding. This is a solution that Citybike user request can be solved. The main frame with the diamond shape and the principle of the gravitational field equilibrium no need to wear all the bike weight on and folded in 2 seconds. Upon opening, just tilt, gravity would give strength to help expand. Slider after folding size is a suitcase size and handlebars can be used as drag handle. Diamond structure help the front wheel steady on it fixed.