Tube Butting In-House

Tube butting 01

Tubing sitting in the comfy chair

I mentioned this earlier but it bears more props:  last night we performed our first in-house steel tube butting tests for main triangles.  Mike S. is managing the tube aspect of the project and he just ran with the tubular ball, worked with Jon Henig—our senior production machinist and frame builder to run some tests.  Actually, only two tests.

What is tube butting?

In short, tube butting is a process which results in a tube that has various wall thickness.  In the bike world, the most common butted tube is on that is thick on both ends and thin wall in the middle sections.  The thick sections, after the tube is coped to become part of a frame, are usually about ¼ to 1/6 of the total length of the tube.

Only Two Tests?

The first test didn’t work well.  We tried to butt in stages.  Big mistake in retrospect.  But, it told us most of what we wanted to know in order to have a successful second test.

The second test yielded a production quality tube.  In fact, we might be able to use the part in our shop bike.  The butting process was slower than we’d like to see but for this project, it worked perfectly as a proof-of-concept.

Secrecy?

Yep.  I’m not going to share how we butt tubes.  It goes against the Open Workbook of the Collaborative.  Regardless, it is one of the few proprietary elements of the Collaborative—primarily because it’s a set of technologies we developed for our titanium and carbon bikes.

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