The Titanium Chumba Yaupon: ATB++
At Bike Gear Database, we live in that no-man's land of cycling that confuses much of the industry where gravel and mountain collide. As much as we love the term ATB, in our opinion it doesn't always fully describe the entire category or range of bikes in it. To us, All-Terrain Bike conjures images of party-pace, flat bars rigs with seemingly old school MTB geometry. On the edge of ATB is a type of bike that we have jokingly started referring to as “grountain”. Grountain is definitely not our term but we think it effectively describes a more serious version of an ATB for endurance racing and deep backcountry single-tracking. Growntain is ATB on steroids.
The Yaupon from Chumba epitomizes this space. With its “adaptable” geometry the Yaupon can be set up as anything for anything—drop or flat bar, grinding gravel or flying down mountains, fully bagged or not. You decide. We absolutely love these unclassifiable bikes that are made to carry anything and go anywhere. We spoke with Vince Colvin the Director of Operations and Product Design at Chumba about the Yaupon and this specific titanium build that has us drooling all over our keyboard.
Who and what was the Yaupon designed for?
The Yaupon is designed for long days in the saddle riding singletrack and fire roads. It is loaded with features for the bikepacker and endurance rider from the material choices and geometry to the frame/top tube bag mounts and cargo bosses. If you like riding to the trail, then all day long or are looking for the perfect bikepacking ride you'll appreciate the thought put into our Yaupon models.
We have learned so much over the years building team bikes and riding with ultra athletes like Alexandera Houchin, Katie and Andrew Strempke. After meeting our design criteria we then see how far we can push the bikes outside of their intended comfort zone. We tested the Yaupon ATB with many combinations of parts across a wide range of trail conditions. From there we can really listen to the rider's goals and recommend the best configurations.
So...Yaupon?!
The Yaupon name comes from the Yaupon Holly plant, which is the only indigenous plant in North America that you can brew a caffeinated drink from. Locally, it is found in our trail systems, usually with a thick grouping of green leaves and sometimes with a bright red berry which birds love to gobble up. We love names that you can say in different ways, some pronounce it Yau-pon some Yo-pawn. I enjoy how the openness of the name speaks conceptually to the duality of the frames design. Yes, I went to art school... Ha!
How does the Yaupon bike differ from your hardtail, the Sendero?
The best bikepacking bike should be totally adaptable for any route. Dropbars, mtb bars, suspension forks, rigid forks, 29er x 2.6” tires to 700x50mm or 27plus x 2.8”. One bike for any ride or event was the goal. After years of fitting riders to gravel bikes and endurance mountain bikes we saw a thread pairing wider drop bars to the shorter stems and slacker head tube angles like on our Sendero MTB.
Compared to our Sendero mtb the Yaupon's top tube and reach are shorter. While the Sendero with mtb bars is designed for 32-60mm stems, the Yaupon with mtb bars is designed for 40-90mm stems. For example: I am 6'1” and ride the large in both models. My Yaupon has a 50mm stem and Beacon XL drop bar 52cm. When I ride the Yaupon with MTB bars I run a 800mm wide bar with 14º sweep and a 90mm stem. On my Sendero a 50mm stem with 800mm wide and 9º sweep mtb bars. On both bikes my back angle is about the same. A more subtle difference on the Yaupon is we have more stack and a larger front triangle then the Sendero for a bigger frame bag zone.
The key to this is balancing the top tube and reach numbers with the seat tube angle. We are controlling the fit numbers and handlebar compatibility with those key measurements. On the Yaupon by pushing past traditional gravel top tube/reach lengths and into mtb territory we are able to unlock that shorter stem. The longer top tube and slack head tube angle give you a lot of confidence riding a drop bar bike on singletrack. This also gets the front wheel more out front then with a gravel/road top tube lengths/geometry. The seat tube angle and BB drop put you over the BB and inside the bike so traction is really predictable.
The Yaupon is a mountain bike that also fits a drop bar. It is a really different starting point to design an ATB from. We've noticed the majority of bikes in the drop bar MTB category are really just gravel bike geometries with larger tire clearances. The Sendero is our go to for something more downcountry, trail or XC focused. Don't run a dropbar on the Sendero. The Sendero is pure mtb and intended to be a fast bike that can handle really technical courses and stay playful.
So what's your beef with gravel bike geometry on a dropbar mtb?
Riding a 100mm stem with a gravel width bar is great on a gravel road on something like our Terlingua with a smaller tire and lower fork axle to crown. On a bike like the Yaupon, designed for races like the Tour Divide and singletrack, a shorter stem, wider bar and slacker head tube angle equals a much more capable bike in the tech, less chance for an OTB and more predictable handling off-road. The Yaupon is designed to be capable. Wide bars also equal more bag space. It all goes back to wanting one endurance bike, the most capable for the widest variation in course conditions whether you build it dropbar or with an MTB bar.
What can you tell us about the Ti Space Yoke?
The space yoke is a 3-d printed, or additive printed, titanium chainstay yoke. The goal here is to provide broad tire and chainring compatibility with the maximum amount of mud clearance. Without the yoke we can't run the massive 22.2mm chainstays and hit the same tire/ring specs. They are super strong, built of 6/4 titanium and heat treated to a Roll Royce Aircraft certification level. We've completely designed the yoke and invested in FEA structural testing to optimize the strength to weight ratio. They are made for us with our own design here in the USA. The downside is they are costly to produce. So, we are happy to announce here we are now offering the Yaupon Ti and Sendero Ti also without the yoke for $3595, $400 lower than with the yoke. Now you can choose either option at 2 different price points.
All of our first prototypes on both models were made with double butted oval chainstays, those frames are still going strong. So this is what you will get for the new lower price. Chainring clearances are nearly the same. Tire clearances are nearly the same. So why choose one over the other? Ride quality!
Why the 22.2mm chainstay with the 3D Space Yoke?
Use this for the most responsive ride quality. This works best for those who like to get rowdy, carry more weight on the bike or want the most performance out of every pedal stroke. Fits a 2.6” tire all the way forward in the sliding dropout.
Why the double butted oval chainstay?
Use this for the smoothest ride experience. The full tube is 3/2.5 titanium so it has more compliance built in and for a lighter rider or those not tackling as rough of terrain it can provide a supple ride quality. Fits a 2.6” tire in the middle of the sliding dropout.
What's amazing about this specific (pictured) build?
This Yaupon Titanium was built specifically for ultra-racing on singletrack and gravel. Its rider just completed the Stagecoach 400 on it! The build features a 48cm ENVE G Series Handlebar wrapped in comfy Wolf Tooth Supple tape, ENVE 35mm stem, carbon post for comfort. A SRAM 12 speed XO1 AXS drivetrain to a 34T oval chainring. For some events they may opt for a 36T oval. The wheelset runs the reliable Schmidt SON Boost Thru Axle SON Dynamo hub to a Chris King rear hub on carbon We Are One hoops, handbuilt here at Chumba. The Force AXS levers have been paired to Level TLM Calipers for mtb level stopping power. Fast Vittoria Mezcal tires are a favorite choice among Yaupon riders, and in this case they paired it to a lightweight, but feature-packed ENVE MTN Boost Carbon fork. For a bikepacking bike this is a light/fast setup! We also sourced the complete Dispersed bag set and a full on-trail repair kit including many small parts, tubeless repair kits, Chumba/Silca Mini-pump, a curved needle kit, and multitool.
How invested is Chumba in the ATB market?
We are all in! We have been designing and riding bikepacking bikes for 9 years now. The first few years we had some of the first 29 and 27.5 plus bikes out there. Over the years we've always tried to offer our bikes with the broadest compatibility and the Yaupon ATB (All Terrain Bike) is the example of where this area of the market will be in the next 5 years. You can already see it coming with more gravel bikes designed around suspension forks and more bikes pointed specifically towards bikepacking.
Riders ask a lot of their bikes doing events like the Colorado Trail Race, Arizona Trail Race and Tour Divide, an ATB is particularly suited to being the ideal bike for any of those routes. Easily optimized for each trail or event. Unique to the ATB category is compatibility with the latest 120mm travel forks and the ability to ride with drop or mtb handlebars paired to these shorter stem lengths.
Are any of your riders currently riding a Yaupon?
Yes, Jerod Foster aided us with feedback on our first Yaupon prototype during the route building of the Great Plains Project. He has been riding his Yaupon with dropbars, SRAM AXS 1x12 gearing, 120mm suspension and rigid forks.
Alexandera Houchin will be racing a Yaupon Titanium as a single speed with MTB bars on this years Tour Divide! We are in the process of building her bike up right now to prepare for the event. We'll be posting an in-process view of this soon, so people can follow along from raw tubes to a complete bike!
Also, Henley Phillips is about to tackle a yo-yo thru-hike then bikepacking back to the South trailhead with his Yaupon as a mtn handlebar configuration.
In-house fabrication and locally sourced materials?
Yes, all of our bikes are made in the USA. We build our bikes in our shop at Chumba USA HQ in Austin, TX. All of our materials are sourced within North America with some shipping to us from Canada. Our titanium tubing is domestic and certified. We use many USA made frame components as well like Paragon Machine Works dropouts, head tubes, bottom brackets and our 3-d Space Yoke is made here as well.
Frames and complete builds are all made to order. We have loads of customization options to choose from. Each frame goes through a multitude of quality and alignment checks, tubes are meticulously cleaned, mitered and deburred then cleaned again before welding. Many of our finish options we perform inhouse or with our local painters. Generally, we build Ti in batches of 4 frames at a time and steel in batches of 7-9. A titanium frame takes us about 2.5 times as long to produce as one steel frame.
Can you put the new SRAM Transmission on a Yaupon?
Yes.
How much does a Yaupon cost and how do we get one?
Our Yaupon Titanium with the SpaceYoke is $3995. Our Yaupon Titanium w/ oval chainstay is $3695. Our Yaupon Steel is $1895, but currently on sale for $1695! Complete builds range from $4K and up. You can order them directly from us or if you are local to one of the dealers we've partnered with, we recommend you work with them.
Thanks, Vince.
