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  1. #1
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    Forged vs CNC'd?

    I've often wondered about these U.S. made hubs and cranks and brakes and whatnot which are CNC'd instead of forged. Can a CNC'd hub really be as strong as a forged hub? A CNC'd crank as strong as a forged crank? It's nice to see stuff made in the US, but when a lesser process is used (or so I've read it's a lesser process) to make something, doesn't it make more sense to avoid them?

    Are rohloff's forged?

  2. #2
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    A forged piece is stronger than something machined from a billet. A forged piece can be (and usually is) finished by machining, though not all surfaces are necessarily touched.

    Equipment and molds for forging are really expensive, so it only makes sense when production numbers are high. This is why a lot of boutique parts are just machined.

    In practice it doesn't seem to matter much. The design of any given part matters much more than the difference between machining and forging.

  3. #3
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    I was about to post the same question. There is an earlier thread though with a lot of technical inputs...

    CNC Macined Components VS. Forged Components???

  4. #4
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    Quote Originally Posted by Gundam168 View Post
    I was about to post the same question. There is an earlier thread though with a lot of technical inputs...

    CNC Macined Components VS. Forged Components???
    Nice find!

    Forging tech is progressing. Some parts are "near net" forged, meaning they need very little machining to fit properly. Thin walls are also possible. Lower cost forged parts that are just as strong, but with less surface finishing are cheaper (less machine time, fewer chemicals, less wasted material, etc.). You might find stuff like that at Performance or Nashbar.
    Nicer stuff with more surface finishing is just as strong but costs more. I think Loaded Components is an example.

    Low quantity runs are likely machined from a billet, which may be made by any number of processes that minimize inclusions (air pockets, poorly structured grain, etc.). Lots of CNC'd parts come out of extruded bars.

    The days of poorly made CNC'd parts are behind the MTB industry for the most part. The 1990's was fraught with fly-by-night machined parts in pretty colors that failed regularly under mild conditions. The industry today demands much more than that, so anyone trying to get in has to bring their "A" game. If they have one failure, they often lose all the business (obviously there are a couple exceptions who have handled their failures in a good way).

    -F
    It's never easier - you just go faster.

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