Jim Clossick's Bamboo Gravel Bike: 206 Miles of Unbound Mud

In the early hours of a Sunday morning in May, Jim Clossick rolled back into Emporia, Kansas, on a bamboo bike he built in his garage. He had been riding for more than 20 hours. Unbound Gravel 200 is 206.9 miles of Flint Hills gravel, and in 2026 overnight rain turned it into what riders called peanut-butter mud. Almost one in five age-group starters didn't finish. Jim did, at 63, on his Gravel Lugged frame. He calls it MNLB: My Next Last Bike.

"The bike held up superbly in a race where many store-bought bikes failed," Jim told us. In October he takes it to South Africa for a seven-day stage race. But first, the backstory, because MNLB is not Jim's first bamboo bike. It's his fifth home-built frame.

Unbound 2026 at a glance

• Race: Unbound Gravel 200, Emporia, Kansas, 30 May 2026 (the event's 20th edition)
• Distance: 206.9 miles (333 km), about 9,000 ft of climbing
• Conditions: overnight rain, sticky mud, more rain, heat and storms
• Field: 1,249 age-group riders started the 200; 1,019 finished
• Jim's time: 20 hours 21 minutes, finishing in the small hours of Sunday
• Bike: Gravel Bike Frame Kit – Bamboo, Lugged: bamboo tubes bonded into pre-formed aluminium lugs, built at home and painted black

The winners were Mads Würtz Schmidt (9:14:51) and Sofia Gomez Villafañe (10:31:37). Nearly 30 per cent of the elite riders didn't make it to the line. Results and conditions: the official ChronoTrack results and race reports from Gran Fondo Daily News and road.cc.

Who is Jim?

Jim lives in Miami and races with the Velo Masters club. He is a biomechanical engineer, and he has been making things all his life. "I have loved to build (and break) things since I was very young," he told us. "Before the bamboo bike I used similar techniques to build wooden kayaks, surfboards and my current ocean-going boat."

Ten years, five frames

Jim ordered his first kit from us in October 2016. He wanted a weekend single speed. "The bike rode so well that I decided that with some modifications I could make a lightweight race bike." Here's how it went from there:

• 2016: the single speed. His first kit, finished at home in Florida that winter.
• 2017: Bamboo II. A road race bike under 17 lb, with joints Jim made in carbon fibre and a Campagnolo Super Record groupset. He raced it in more than 25 criteriums, road races and triathlons that season, with several podiums.
• 2019: a century win. On a 100-mile club ride from Homestead, Florida, Jim got into the break, attacked at 65 miles and rode the rest alone to finish first.
• 2020: build number three, with our tapered head tube.
• 2022: Balsaro. An experiment in balsa wood with mahogany inlays and handlebars he made himself, built with our parts, jigs and techniques.
• 2023: fifth in a national race. Jim told us he took fifth in the 40 km road race at the National Senior Games in Pennsylvania on his bamboo bike.
• 2026: MNLB, a Gravel Lugged kit built for Unbound.

On his first criterium on Bamboo II, Jim wrote to us the same night: "The true test of a bike is to go into back-to-back right and left 90-degree turns at full speed. The bike handled like it was on rails. No flex when I accelerated coming out of the turns."

Balsaro taught him a lot, and he shared the lessons with us. "You can make a bike that is too stiff. I reinforced the frame too much with carbon fibre. Balsa absorbs more resin than you would think. And the tube wrap, the number of wraps and the pitch, is critical to stiffness and strength."

Building MNLB

Jim ordered his Gravel Lugged kit at the end of December 2025 with one goal: "I'm planning on riding this bike in this year's Unbound 200-mile race." He asked for the straightest bamboo we had. The lugged kit skips the wrapping stage: you cut and mitre the bamboo, then bond the tubes into pre-formed aluminium lugs.

The kit arrived in February and he built it at weekends through the spring, then painted the whole frame black and lettered the name on the down tube.

Why Unbound is such a test

Unbound is the race most gravel riders have heard of. It started in 2006 as the Dirty Kanza and now draws the sport's biggest names. The 200-mile course loops through the Flint Hills of Kansas on rough, rocky farm roads.

The 2026 edition was one of the hardest yet. Rain overnight turned sections to thick mud that clogged wheels and drivetrains. More rain came after the first 100 km, and some sections were flooded. One pro summed up her day as "mud, rock, heat, rain, thunder, hail." Even the leaders had trouble: the men's winner cut a tyre and had to change a wheel. Romain Bardet, the former Tour de France podium rider, stopped with a mechanical problem he couldn't fix.

Age-group riders like Jim face the same course for twice as long. He started in the morning and was still riding at 2am.

Next: seven days across the Karoo

Jim is now heading to South Africa for the Nedbank Gravel Burn, from 25 to 31 October 2026. It's a solo stage race across the Great Karoo, from Graaff-Reinet to the Shamwari game reserve in the Eastern Cape. The organisers list about 750 km and 8,500 metres of climbing over seven stages. Riders sleep in moving camps, and the last stage crosses Big Five country with rangers on the route. This is only the second edition, it was founded by the creator of the Cape Epic, and its 500 places sold out. Jim will line up with Unbound runner-up Matt Beers, the defending champion, and a provisional field that includes Tom Pidcock and Nino Schurter.

He asked us for a spare rear derailleur hanger to take with him, just in case. We'll share how it goes.

Build your own bamboo gravel bike

Jim built MNLB from our Gravel Bike Frame Kit – Bamboo, Lugged. You bond bamboo tubes into pre-formed aluminium lugs, so there's no wrapping, and it comes with step-by-step instructions. If you'd rather wrap the joints in flax fibre, there's the wrapped version too. Thanks, Jim, for ten years of builds and race reports. Good luck in the Karoo. If you've built one of our kits, email us your photos. We'd love to feature your bike next.