Moots Cycles: The Difference is the Tubing.

I’m going to talk for a few posts about my recent trip to Steamboat.  At the outset of those posts, I’m going to talk a little bit about why I believe Moots is an extraordinary company.  For today, I’m going to talk about tubing.

Yes.  Tubing.

Tubing is the heart of any bicycle, whether it be built from carbon, bamboo, aluminum, steel, or (my personal favorite) titanium.

It should be relatively self-evident that a tube shape is not a normal shape for metal to come in.  You can make metal in a sheet relatively easy, or can make it into a block.  You can even make it into a solid casting or forging relatively simply…or take a solid piece of metal and CNC it out into a complex shape.  But a tube…a tube is an irregular shape.

There are two common ways to make a structural tube.  The most common way is to start with a piece of sheet, bend that sheet into a tube, and then weld the seam together to make a tube.  This is commonly referred to as ERW or electric resistance welded tubing.  ERW tubing is relatively easy to make, but results in the tubing having a welded seam.  That welded seam is always a point that has a different amount of strength than the rest of the tube–it is a stress point, and a potential weak spot.  When you’re bending tubing, you try to put the welded seam in the inside of a bend, as that minimizes the stress on the welded joint.  There are two problems with this, however: 1) the welded joint is still a weak spot; and, 2) if you have a tube that bends in more than one direction, you cannot have the seam on the inside of all of the bends, so you will have a bend with a weld in the weakest possible spot.

It’s not a real disadvantage, but ERW tubing is also an inelegant solution…and if you see the welded joint on the inside, it’s ugly.  You can polish the exterior of the tube to eliminate the obvious joint, but it’s still not doing it pretty.

The other form of tubing is known as DOM or drawn over mandrel.

Moots uses DOM tubing.

What is DOM?  DOM means that they essentially take a solid block of titanium, and pull it over a heated up mandrel–think a heated up solid rod or bullet.  As the block of titanium is pulled over the mandrel, it makes the ‘hole’ in the middle of the tube.  The outside of the tube (the walls of the tube) are formed into the shape of the tubing.  You can vary the wall thickness and diameter of the tubing by changing the tooling on the mandrel.  DOM tubing may also be referred to as seamless tubing–because (as the name implies) it is seamless. Why is that important?  No weak spots.  None.  You can bend it in any direction, without having any weaknesses.  You can do complex bends in multiple directions, without having to worry about seam orientation.

There are a surprising number of bike companies that use ERW tubing.  Among those that use DOM tubing, many use imported tubing.  What about Moots?

Moots uses tubing that is made in the USA.  More specifically, tubing that is mined and manufactured in the USA.

Sandvik Special Metals in Washington makes the tubing to order for Moots, and ships it over in wooden crates.  The tubing can cost upwards of $30/foot, so a 20 foot stick of tubing represents a significant investment in itself.  A wall of tubing (as shown above) is tens or hundreds of thousands of dollars.  The lead time on ordering the tubing is measured in years, not days…so Moots is presently ordering tubing that will be used in bikes that they haven’t yet designed.

In the factory, there’s tubing everywhere you go.

Everywhere.

Everywhere.

So in short, Moots is using the an amazing material: titanium.  They’re not just using titanium–they’re using DOM tubing.  And not just any DOM tubing–they’re using DOM tubing mined and made in the US.

I’m going to talk about tubing more.  Get ready for it.

The whole Moots Series:

Moots Tubing

Moots Bends

Moots Miters

Moots CNC

Moots People

Moots Welds

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2 thoughts on “Moots Cycles: The Difference is the Tubing.

  1. 1. The majority of titanium tubing is eaten up by the aerospace industry, thus the long lead time
    2. Most of the world’s titanium tubing is American-made with Sandvik being one of the larger companies, and happens to be a Swedish company
    3. The weld is in almost all types of welding processes the strongest part. It is the adjacent heat affected zone, or HAZ that is the weak point.

    • 1) Yup. Unless you’re willing to use imported titanium that doesn’t meet aerospace standards.
      2) From what I’ve found, this isn’t exactly accurate.
      3) Agree–and that’s what I posted. The seam is a stress point and potential weak spot. The weld itself, if done properly, is probably stronger than the surrounding metal…but that creates a stress point in the adjacent metal. That stress point is exacerbated if the tubing is bent…particularly if the bend is on the outside of the bend’s radius, rather than on the inside.

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