Framebuilding tools

The Bridge Miter Matcher

Since the beginning, we’ve built many of our own fixtures and jigs to build bike frames. This Bridge Mitering tool is one of the most useful and unique small fixtures we’ve made, so now we’re offering it to other framebuilders.


This fixture is designed to hold a seatstay bridge in the milling machine for mitering, and it will place both miters at the same angle, the same distance from center. It works with curved or straight bridges and is completely repeatable. No crooked bridges or uneven miters. Burning bridges has never been more enjoyable!

The way it works is the base block is clamped in the mill vice at the miter angle (or bolted to the table in the case of a horizontal mill) and the clamp block is bolted to the top. The clamp block holds the bridge, and is indexed for two positions 180 degrees from each other. A miter is made with the block in each position, and you’re done. The clamp block is removable, so you can carry it over to the frame and see if the bridge fits. If you need to take a little more off, you simply bolt it back on to the base block, and you’re right where you left off, so you can take a measured amount from each side. It’s also extremely useful if you’re doing batch runs of frames, since you can make several bridges exactly the same.


Each clamp block is designed for a specific size of tubing. The tool comes with one clamp block size, but other sizes can be ordered (once available), and they will all fit the standard base block.

-The 38mm clamp block will work for bridge miters between 38 and 74mm apart. This is good for most gravel, mountain and fat bike frames. Check your drawings and ensure that this range will work for your applications. They are available for 1/2″ or 3/8″ tubing, and each size works with curved OR straight bridges.
-This tool is machined manually, by a framebuilder, in Colorado, USA.
-Eventually we will offer more clamp block options for extra-narrow road bridges and more.

The Bridge Miter Matcher is available in our Webstore.