I'm going to keep this one short and sweet.
Butting is a term thrown around a lot in frames, forks, bars, spokes, etc. Anything with tubing, really. But what is butted tubing? Well, simple the thickness of the metals varries, instead of being constant.
Butting is a term thrown around a lot in frames, forks, bars, spokes, etc. Anything with tubing, really. But what is butted tubing? Well, simple the thickness of the metals varries, instead of being constant.
It's really simple to understand WHAT it is. Internal butting is used in frames, for example. Top Tubes don't NEED to be thick in the middle. So, butting allows the tubes to be thick where it needs to be (at the ends, for welding), and allows the frame to be thinner and lighter where it can be (in the center, for example).
External butting is also used in frames. For example, look at the Mankind Archangel frame:
External butting is also used in frames. For example, look at the Mankind Archangel frame:
It may be hard to see, but the seat tube actually is thinner in the middle! External butting is used where the inside of a tube needs to stay a constant diameter. In the example of the frame, the seat post needs to go in and stay vertical.
External butting is also popularly used in spokes.
In the technical drawing above, both tubes are butted. It may be confusing to think about, when you hear "double butting", you think "okay, there are 2 steps down in thickness." however, it's much different. Still simple, though
Butted: The tube varies in thickness at one end
Double Butted: The tube is thicker at the ends, and both ends are the same thickness
Triple Butted: The tube is thicker at the ends, but the ends are of varying thickness
Quad. Butted: The ends and center are of varying thickness.
Straight Gauge: No change in thickness. .
External butting is also popularly used in spokes.
In the technical drawing above, both tubes are butted. It may be confusing to think about, when you hear "double butting", you think "okay, there are 2 steps down in thickness." however, it's much different. Still simple, though
Butted: The tube varies in thickness at one end
Double Butted: The tube is thicker at the ends, and both ends are the same thickness
Triple Butted: The tube is thicker at the ends, but the ends are of varying thickness
Quad. Butted: The ends and center are of varying thickness.
Straight Gauge: No change in thickness. .