Custom fillet Brazed bicycle frames is the choice for bicycles produced at Peyto Design Works. Fillet-brazed bike frames are strong and have a lugless smooth clean appearance, but they are uncommon because of the additional craftsmanship required. Lugged bicycle frames, for example, are now manufactured by automated machines. Peyto Design Works still provides fillet-brazed construction on all our custom bicycle frames.

Fillet Brazed

What Is Fillet Brazed Construction?

Fillet brazed is a term that originates from the French word for ribbon. Fillet brazing is a construction technique where the builder joins tubes without the use of lugs or welding. A brass brazing rod is used in the process and with several passes creates a small mound around the joint called the “fillet.” Fillet Brazing is otherwise known as Luggless Construction because the framebuilder is free to use any angle and any tube diameter, in other words not limited to the constraints posed on the builder by using lugs. It is also argued to be the most aesthetically pleasing of all the joining methods. A high quality fillet brazed joint gives the illusion of one tube seamlessly blending in to another. In this method of bicycle frame construction, “mitering” or cutting the tube ends so that they fit together precisely is critical so that capillary action will draw the molten filler into gaps for a strong joint.

A high quality fillet brazed joint gives the illusion of one tube seamlessly blending in to another. Layering brass over the joint, then filing or sanding away any excess to leave a smooth radius accomplishes this effect. The frames produced by fillet brazing are as strong as using any other joining method. Fillet Brazed frames tend to be a little heavier than a lugged frame due to the amount of filler material used in the construction of the joint, for this reason these frames might be more suited for a mountain or touring bike, however roadies might also find them asthetically pleasing as well.

The advantages of fillet brazing are described below:

Versatility: With fillet brazing it becomes possible to join tubes of various diameters and shapes that lugs may not even exist for. If the tubeset you desire does not have lugs available for it (as is the case with many oversized tubesets) fillet brazing becomes necessary. Or, if the geometry of your frame deviates significantly from the norm, a fillet brazed construction is called for.

Reduced Temperature: Steel tubing develops weaknesses when heated. We avoid T.I.G. welding for just this reason, as it brings the tubes to 2,000 degrees F. to actually melt the metals together, By contrast, fillet brazing hovers below 800 degrees. Therefore, it never takes the steel to its critical melting point and stresses are dramatically reduced. For this reason, a fillet brazed frame often survives crashes better than a T.I.G welded frame.

Appearance: Because fillet brazing yields an elegant seamless transition between tubes which creates an elegant and contemporary finish which you may prefer to lugs — assuming your design and tube set allows you the freedom of choice.

Tig Welding

Custom Mountain Bikes, Cyclocross, Road, Street, Road, Trials bikes, Dirt Jump, Freeride, Single Speed, and 29er Bicycles.