how are bike parts made in general?

Question

For example bmx barends. how do the companies make the bar end shape. is the metal molded, melted, welded, pressed? how do they do it. for frames and even rubber bmx grips too. any answers or websites would be great. thanks

Answer 1

All of the above.

Many flat metal parts are stamped in a giant press, then possibly machined a bit. Most tubular parts are made from the appropriate material and either bent or cut and welded to shape.

Weird metal shapes, like the body for a derailleur or a handlebar stem are often forged while plastic and nylon items start out as little pellets which are heated and forced into molds.

So, if you want to discover how different things are accomplished, do searches for:
Forging
Die Casting
Injection Molding
Welding
Tube Bending

This should be enough for you to start with!

Answer 2

Fluid forms would be moulded. Many bike frames, however, are simple tubes, which are then welded together. These tubes can be treated, or manipulated during production to enhance the strength or organic look.. The rubber grips are injection moulded, similar to plastic model kits. Gear pods are machine assembled.

Unfortunately, although you are asking a cycling related question, the actual topic is light engineering, and fabrication. You might get more detailed answers asking your question in another category.

Luck