Specifications

Philosophy
The goal of Kirk Frameworks is to build bicycle frames with unsurpassed craftsmanship and attention to detail. I aim to make the process of designing and building your dream bicycle a rewarding experience for you, with customer service and attentiveness that can only be found in a small operation.

I build simple, functional, durable and beautiful machines. I believe that a frame that is properly designed and built is likely to please the body and the eye, as well as the spirit. A truly good frame can create an experience like nothing else.

What's the deal with frame flex?
I'd like to share my thoughts about frame flex with you, as I believe this is a widely misunderstood topic. These are thoughts and conclusions that I have come to after 15 years of being a professional builder and 25 years as a serious cyclist. Click here to read the article.

Materials
Kirk frames are made exclusively of brazed steel.

I use steel because it offers many advantages, including:

• Ride quality
• Fatigue resistance
• Availability of tubes with a wide variety of specs
• Cost
• Reparability.

Steel's combination of stiffness and fatigue resistance allows smaller diameter tubing compared to titanium or aluminum. Tubing diameter is one of the main factors that influences ride quality. For example, aluminum tubing needs to be large in diameter due to its poor fatigue resistance. Titanium, on the other hand, is much more flexible than steel so it needs to be large in diameter to be stiff enough to handle properly and transfer energy. Steel tubing offers a balance of a supple ride and durability that make it a choice building material.

Brazing
Traditional brazed joints are the choice for Kirk frames. Some advantages of brazed joints are:

• Lower heat compared to welded joints
• Smaller heat-affected zone
• Allows for the use of thinner tubing
• Aesthetic qualities

Brazing heats the steel to about 1,800 degrees F - just hot enough to allow the brass or silver to melt and flow into the joint. Welding, by contrast, heats the tubing to its melting point (around 3,500 degrees F). At this temperature annealing occurs in most tubing, causing a weakened area adjacent to the joint. Brazing allows for a much smaller heat-affected zone than welding. The use of lugs or fillets spreads the load over a larger area than a welded joint. This can allow the builder to use thinner tubing for a given size rider, without risking failure.

Moreover, I believe a properly built lugged or filleted frame is the most beautiful way a bicycle can be constructed.

Tubing
Having worked with nearly every type of steel bicycle tubing available, a few brands stand apart from the crowd. In my experience Reynolds, Dedacciai and Columbus all offer excellent tubing. Each brand of tubing has its benefits. Specific tubing will be selected based on you and your needs.

Fillets
If you like the organic, flowing, seamless look for your frame, then fillets are the way to go. If your bike requires over-oversize tubes, fillets may be the only option.

Decals
There are 5 basic decal colors: blue, grey, green, red and orange/yellow. Each decal color is available with a white outline or a black outline, so it can go on either dark or light paint. There are a variety of decal sizes so you can mix and match to your heart's content. See all the decal options on the decal page.

There are many options available to suit nearly any need or taste. Call me and we can discuss the options and come up with a bicycle that is perfect for you.

Learn more about frame fit... >>