Paul’s klunkfat

Paul loves his Surly ICT with drop bars and 27.5×4″ tires but was wanting to make a Ti version but with a narrower rear axle, Q-factor, and chainline. Unlike the Surly, this frame maxes out at a 4″ wide tire and has a 177 rear axle spacing instead of 197. It’s got sliding dropouts to make it into a singlespeed or to tune ride characteristics and fit different sized tires by adjusting chainstay length. But it fits a 27.5 x 4″ Terrene Cake Eater on a 80mm wide rim all the way forward at 435mm CS length thanks to using Rollingdale Cycle’s beautifully machined yokes on both sides. I maxed heel clearance by using the OG Paragon tab sliders – hard to do when using bigger diameter Ti tubes! But because of the RDale yokes this is as good as it gets. It’s got a massive 230mm long tapered internal bearing head tube that’ll blend nicely with the tapered steerer Oddity Squid fork. The stack is super high to be comfy when in the drops using no stem spacers.

This frame involved some firsts in design and fabrication for me. I enlisted the help of Daniel Yang to help with the top tube/seatstay design since when I did Jay’s Klunkpacker in steel I pretty much got lucky (I did that my normal way – winging it). But with bigger tires needing greater tube bending angles I was fortunate that Daniel worked with my BikeCAD design and converted it into very detailed CAD drawings (see below) and we brainstormed the bending process to ensure success. Sounds easy but it was a headscratcher! Messing up with Ti is very expensive at $3-5 per INCH, so getting the bends from head tube to dropouts dialed in one take was a high priority. The time in design vs. fabrication was flipped in this build. Although it took a long time to build, it took a lot longer to figure out a design that would work with the tubing benders and radius dies i have while incorporating the large amount of springback Ti tubing has when bending. The twin top tube braces were one of those little details that sidetracked me while i figured out where to put them, how to make them and fixture them, and setting up the system of backpurging them (I set up a second torch to purge the backside of the plate and cradled the area in a tinfoil dam).

As with most bikes, it’s all been done before, only this time by me. There’s only so many ways to do a twin top tube frame without raising standover too much so it has the look of a Torker or more recently a Moonlander. The frame and rack are in Ft. Collins with Oddity right now getting a custom finish and fork so i’ll update this post with more photos when it’s all built and ridden!

Some process pics for the build are shown below. I always take a lot of photos to keep in albums for each complicated build so that if someone else wants this style frame I can refer back to the photo album and remember how i did everything.