Originally Posted by
Andrew R Stewart
I will agree that these dropouts look to be "better" than simple plate steel stampings. Given the shaping I suspect they have been "formed" by serious pressure, whether one calls that "forging" is not for me to say.
I also agree with John and others who say don't replace a working thing.
It's also nice to have the full story with to best understand what is actually going on. The more data we have the sooner the fewer assumptions we will make as we try to help. Andy
those were most likely Stamped, Forged, then Machined.
some are Cast,, then forged and machined.
some BMX, "waterpipe", Aluminum, and single speed dropouts are Stamped then machined, since they are typically flat and don't require being shaped by a forge.
Cast Dropouts are stiffer, but cracks can more easily form in the material if it's bent then straightened.
rolled steel has a longer grain structure that limits cracking when bent, but is also more easily bent in the first place. rolled steel sheets are used as the base material for Stamped Dropouts.