Aluminum bicycle frames are usually made of lengths of tubing, joined together at the ends by welds. The CNC eFanes electric enduro mountain bike is different, though, in that its frame is milled from solid 6061 aluminum … and it costs €15,999.90, or about US$18,630.
Manufactured by German bike company Alutech, the CNC eFanes’ frame is appropriately enough created via a CNC (computer numerical control) milling process. In a nutshell, this technique involves utilizing a computer-guided milling machine to build items by selectively removing material from a solid block.
In the case of the CNC eFanes, the two sides of the frame’s main triangle are milled as two separate pieces. These are then welded together clam shell-style, so there’s a weld seam running laterally down the center of the frame.
That seam isn’t as noticeable as typical aluminum welds, though, due to the use of a special shielding gas that allows the welding to be performed at a lower-than-usual temperature – this means the metal doesn’t become as distorted as it would otherwise. Additionally, the weld line is completely polished away on the top of the top tube.