Folding Gravel Concept in stainless steel

The first folding frame I developed for ease of airline travel was a mountain bike. Which worked great as proof of concept. From there I added pivots at the seatstays for an easier pack which became the first FRC (Folding Road Concept). The first folding frames I did with disc brakes used a taller dropout to allow the pivots to be above the chainstay mounted caliper so that the seatstays could still fold down over the chainstays.

With the addition of thru-axles I decided to try a new solution where the axle acts to lock the seatstays into the dropouts, allowing the seatstay unit to be removed from the frame instead of folding. This bike is the first prototype with this system, being also built in stainless steel.

Being a prototype gave me the opportunity to test out some other components as well as the new frame configuration. For ease of working on the bike when traveling, I wanted all mechanical controls – starting with Campagnolo 12spd Ergopower shifters. These operate an Ingrid rear derailleur that shifts the SRAM chain across a 10-48 Garbaruk cassette, driven by a 44T chainring on a Garbaruk crankset. Braking is handled by Growtac Equal disc calipers and 160mm Galfer rotors.

The left-hand shifter was gutted to allow it to operate the Enve dropper post. This post has internal cable routing, so to accommodate removal for packing, I created a cable de-coupler that tucks into the seattube.

For this bike I wanted a more capable gravel bike than I had built for myself before – this meant larger tires; the build is shown here with 45mm tires, but 50mm will fit. The seattube is offset on the bottom bracket shell to provide the needed tire clearance whilst maintaining short (425mm) chainstays. The geometry has a larger trail figure (70mm) for slightly slower, more stable handling, and a longer toptube/shorter stem for better weight distribution.

I have not traveled with the bike by air yet, but have been very pleased with it in terms of the riding design goals. The esoteric component mix all works well together, with accurate shifting, powerful braking and a very quiet drivetrain. The tires and geometry give more control and confidence on rough terrain, and after I got used to the dropper seatpost, that has proved to be a useful addition for technical and long descents.

The final weight came in at 18.1lbs without pedals.

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