In my 20+ years of being a framebuilder there has always been one frame part that left me cold and that has been the rear dropouts. Over the years I’ve had the chance to design a few dropouts but time and budget always compromised the design. Well being on my own has allowed me to design the dropout I’ve always wanted, cost be damned.
Enter the “Triple F’ dropout. The name “Triple F’ stands for “Form Follows Function” and as you can see there is nothing extra or blingy about these dropouts. They are designed to be as minimalist as possible while still being strong enough for the largest rider to use the rest of their lives. The Triple F is machined from 4130 steel which is stronger and more fatigue resistant than most of the stainless dropouts on the market so the chance that one will ever break is almost nonexistent.
The simple design allows for the stays to be square cut on the ends and eliminates the need to slot the stays or give them a compound angle miter. This saves a huge amount of time. In my testing and prototyping I’ve found that I’m saving about 45 minutes per bike using the Triple F compared to a Breeze style dropout and even more when compared to a traditional plate style dropout.
There are two balls machined into the dropout for the stays to attach to and they allow for stays of different diameters and wall thicknesses to be joined to the dropout and almost any angle. This makes it simple to build most any sized frame and to attach curved stays if the builder wishes. The square cut ends of the stays mean that it’s quick and easy to get the stays to the exact right length – a few seconds on the disc sander is all it takes and there is no need to file a slot deeper into the stay to get the right length. The ball and socket interface also means that the builder can rotate the stay to the desired position on the dropout to get bent or ovalized stays to be in phase with one another.
Stays can be attached to the Triple F by either fillet brazing or TIG welding. When fillet brazing the heat is applied to the concave surface nearest the axle slot to preheat the ball and then brass can be pulled into the joint. The acute angle that the inside of the stay makes with the ball allows the builder to form a large internal fillet for strength and a small aesthetic fillet on the outside to blend the stay and the dropout together seamlessly.
The Triple F is also designed to be a ‘centerline” dropout – meaning that the axle lands the centerline of the chainstay. This means that the angle that the chain stay leaves the bottom bracket is true and that the stay will not be loaded into the BB socket at an angle. For anyone that has built lugged frames with Breeze dropouts this is a big deal.
I suppose many of you are wondering why I am sharing all this detail. It’s because as of today I am offering the Triple F to other insured framebuilders to use in their own frames. Because I’ve picked what must be one of the most complex shapes known to man to machine they aren’t cheap. But there is much time and frustration to be saved in using the Triple F and and I suspect that for many builders the cost will be more than worth it. The cost for a pair of Triple F’s is $110 plus shipping and they are only available to builders who can show proof of insurance. I have a one time offer to allow builders to try a single pair of Triple F’s at a lower cost of $85.
Interested builders should contact me by phone (800 605 5475) or email (info@kirkframeworks.com) to ask questions or place orders.
These dropouts are the first in what I hope will be an ever expanding group of framebuilding parts for the discriminating professional builder. The first product was the brass barrel adjusters, now the Triple F rear dropouts and the matching Triple F front dropouts are next on the horizon.
Thanks for looking.
Dave
