Chumba Yaupon Steel: Drop-Bar 29er Gravel Mountain Bike

A drop-bar mountain bike sits in the gap between a gravel bike and a hardtail. You get the hand positions of a road bar, with the wheels, tires and frame strength of a mountain bike. For bikepacking, rough gravel and long days on singletrack, plenty of riders think it's the best of both.

This series looks at drop-bar 29er gravel mountain bikes built on Boost spacing, the wider hub standard used on modern 29-inch mountain bikes, one brand at a time. Boost matters on a drop-bar 29er for three reasons:

• Any modern mountain bike wheel fits. Spares, upgrades and loaners are easy to find.
• Suspension forks drop straight in. Most current 29er cross-country forks are Boost, so a rigid bike can take a suspension fork later, or the other way around.
• More room for tires. The wider spacing helps make room for big tires on a frame short enough to handle well.

First up: Chumba's Yaupon Steel.

Chumba Yaupon Steel

Chumba built the Yaupon to swap between dirt drop bars and flat bars.

Specs

• Frame: Chumba oversized double-butted steel, with an optional USA-made heat-treated tubeset; also available in titanium
• Fork: Chumba lists 100mm to 120mm suspension forks, and rigid options like the ENVE MTN Boost Carbon 29er fork
• Spacing: 148 × 12mm Boost rear
• Tires: 29 × 2.4" in every dropout position; 29 × 2.6" from the middle position back
• Price: frames from $1,695; complete bikes from $5,000

Photo: Chumba USA

In Chumba's words

We asked every brand in this series the same question:

What makes your product different or special as a drop-bar mountain bike for riding gravel?

The Yaupon is not just another gravel bike, geo-inflated with big tire clearance. It has unique geometry with a longer top tube and reach than typical gravel bikes. You get improved big-tire handling. Pair the longer top tube and reach with a shorter stem, and you get comfort on wider bars, confidence-inspiring predictability over rough terrain, and the ability to run front suspension without twitchy handling. The Yaupon is meant to take you from the gravel into the backcountry with a geo like that!

At Chumba we handmake our bikes to order, so you have the ability to customize the frame with mounting points, fit geo changes and much more. Looking to plan a bike? Hit us up by email or phone!

— Vince Colvin, Partner, Chumba USA

Photo: Chumba USA

Who it's for

Riders who want one bike for gravel, bikepacking and rougher backcountry trails, with the option to run front suspension, and who like the idea of a frame built to order with their own mounts and fit tweaks.

See the Chumba Yaupon Steel

Follow Chumba on Instagram: @chumbausa

Prices are as listed by Chumba in late October 2026. See the full drop-bar 29er gravel mountain bike series. Know one that belongs on the list? Tell us at hello@gravelgeeks.com.