WITH THE BIKE - AND IN THE SUBWAYBut not to throw out it! And involuntarily thought creeps in to make it a foldable frame. The same as, say, the “Kama”. I reviewed the literature on the subject (including the publication in “M-K” № 3, 1990) and left unsatisfied — too difficult was the recommended design. Had to develop my — more simple. Tried it and now offer to the readers.

In recent decades the world is experiencing a Cycling boom. Bike on the planet today — the vehicle number one, even the car behind him the palm of victory: for each four wheeled machine has two two-wheeled.
A Bicycle does not pollute the atmosphere and improves health. The author, in the past an avid motorcyclist and motorist have long switched to the bike. Every year I “cheat” and a half-two thousand kilometers and I feel great!
A normal road bike, I ride quite satisfied me. It is durable, easy, reliable and durable. However, its benefits fade as soon as I get up with him on the platform to the train. And very bad in the subway: it is necessary to remove the front wheel, and where to put it and how to be sticking a fork?! Finally, uncomfortable and cumbersome. in the apartment.
Typically, the foldable bike two connectors in a vertical plane: one on the horizontal tube of the frame, the other on the sloping. Options of hinges for these connectors are numerous. My task was to develop the most simple. I stopped on the loop structure of the type with constipation in the form of a conventional bolt with a nut which in the case of loss or wear of the thread can always be replaced.
The device and the joints are easier to understand from the drawings. Of course, even such simple knots not to manufacture, so I ordered them in a shop where there was a lathe and milling machines. Material for components was ordinary steel 35.
Marking frame
Layout frame:
1 — the section line; 2 — hinge top; 3 — bottom hinge.
Upper hinge

Upper hinge:
1 — axis hinge; 2 — cheek front; 3 — rear cheek; 4 — sleeve split; 5 — a bolt, nut M8.
Lower hinge

Bottom hinge:
1 — axis hinge; 2 — cheek front; 3 — rear cheek; 4 — sleeve split; 5 — a bolt, nut M8.

While I carried out my order, I altered the frame. It is clear that the folding bike is better in half. However, if you cut the frame along the line equidistant from the axes of rotation of the wheels, the axles will abut each other and the folded bike will not be compact. Therefore, the cutting line I shifted 50 mm in the direction of the rudder below the bottom hinge was away from the sprocket and it does not interfere with the frame free to fold. The design of the joints provides for a folding bike from left to right (clockwise). In this case staining the chain is hidden between the wheels.
The hinges to the frame I soldered the brass using a gas burner. As a flux used is borax. Those who want to simplify this procedure, it is possible instead of soldering to use M6 bolts with nuts. And for that drill bushings of the joints of the hole together with the pipe frame, after checking the correct installation of the hinges. Only during the operation will have to sometimes check and tighten nuts. But if rasklepat protruding ends of the bolts, then pull up anything not necessary.
Folded my bike is simple: I turn on the hinges of the two nuts, move the steering wheel take the front wheel clockwise until until the frame fold in half. Loosening the retaining nut, turn the wheel 90°. In this position and fix the parts of a Bicycle strap, so they don’t leave. And the nuts of the hinges back so nothing gets lost.
Now I have road no problems. Folded it in half, placed in a case made of thick fabric (no larger than 1×1 m), cinched elastic on the neckline and enter yourself into the train or down into the subway. Convenient!

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