When I first laid eyes on the Chumba SLACKR Ti, I could've sworn it was a Sendero—a bike I've been quietly crushing on for a while. The anodizing job and sleek aesthetics pulled me in for a closer look. But then, I noticed something that stopped me in my tracks: that long travel fork. It's not every day you come across a titanium hardtail sporting a 150mm fork, so naturally, I reached out to Vince Colvin of Chumba to get the full story.
I've only ridden a few long-travel hardtails in my life, and I've always wondered where they fit into the bigger picture. In my mind, hardtails have been synonymous with longer distance cross-country rides, capable of getting you through the deep stuff. But the SLACKR isn't that kind of bike. It's a purpose-built machine for rougher, more technical trails—aggressive, yet stable, with geometry and travel designed to push the limits of what a hardtail can do. Sitting in a unique space between full suspension and downcountry, the SLACKR offers a new category of hardtail riding. Vince shared how the SLACKR was born from customer feedback and real-world testing over the years, fine-tuned for riders ready to tackle the gnarliest terrain with confidence.
Let's go.
How did the SLACKR Ti come to be?
Over the years, we've gotten several requests for custom Sendero's built around a 140-150mm travel fork. Rather than dilute the Sendero's purpose, we wanted to build a long travel hardtail platform with its own design and geometry. Enter the SLACKR…
For the last two years, I've been riding my Sendero Ti downcountry hardtail much like a trail bike: Cane Creek Helm 130mm fork, 5dev cranks, Cushcore, etc. It started to become clear that riders like that could benefit from more travel. A new geometry optimized around the concept was worth pursuing. Our designs generally spring from a meeting of customer requests and inspiration. If we can't wait to ride it, other people will feel the same!
Why long travel now?
Based on prior experience, a 150mm travel 29er was too much on a hardtail. That opinion formed about 7+ years ago, having tested it extensively around 67º-ish head tube angles. Back then, forks were less sophisticated, thoughts around geometry angles were very different, and the bikes felt sluggish for all-around riding. In the meantime, forks and components have changed so much. Geometry concepts have evolved alongside those changes. The bike industry has embraced shorter fork offsets paired with slacker head tube angles. We've all been gravitating to slacker head tube angles, more reach, and steeper seat tube angles, resulting in longer front centers paired best with shorter stems and wider bars.
When you combine the SLACKR's geometry with a 150mm suspension fork with modern tuneability, a 44mm fork offset, and a short 35-50mm stem, the effects of the suspension change on the head tube angle are not particularly noticeable while riding. The 64.5º head tube angle makes the travel change feel incredibly natural. It keeps the bike tracking and wheel traction engaged. Riding the SLACKR prototype, the travel felt bottomless. The rollover is unstoppable. The bike still had that pop and playfulness we were after. It wasn't sluggish and pedaled efficiently. I had to change my opinion! Now, the SLACKR is my primary MTB.
What can you tell us about its geo and purpose?
This is the slackest mountain bike we've ever made. We combined 150mm fork travel with a slacker, but not too slack head tube angle, 64.5º (un-sagged) / 65.8º (sagged 20%). The SLACKR's 75/76-ishº seat tube angles are steeper than the Sendero, but slacker than the industry trend on “too far” trail bikes. We've been calling it “slacker where it counts.” We wanted to make a shreddy all-day pedaling platform, not a park bike! Our BB drop is low, but not too low. Balance, maneuverability, and stem choice are all key in the design. We made the SLACKR in 6 frame sizes so you don't end up in between.
How does this thing feel on the trail?
The goal was a capable trail bike that pedals like an overbuilt downcountry bike. It had to be super fun, poppy, efficient at pedaling, able to rail corners, and balanced for airtime. Austin has steep ledgy downhills, but then you've got to get right back up. Instead of long climbs/descents, we have fast and steep ones. At speed, the SLACKR makes it easy to boost off a rock or feature and land past the chunk. Add a capable wheelset/tire combo, and it will track right through the rough.
At slow speeds, because of the long reach/front center and the rider's position on the bike, it is intuitive to thread through the tech. We were careful not to get the BB too low, so you avoid excessive rock strikes and still get that snap and pop out of quick pedal strokes to crest obstacles.
3D printed yokes seem to be a thing these days...
Totally. To our knowledge, we were the first to offer a 3-D printed 2-sided titanium yoke four years ago! 3-D printed or “additive manufactured” yokes offer increased stiffness at the BB zone and total optimization of max tire/crank/chainring compatibility. For example, we can clear a 2.6” tire, 36T chainring, and even narrow XC cranks. We call ours the “Space Yoke.” Compared to a CNC equivalent, we can make a stronger, lighter part with less material waste! Ours are made for us through Silca in Indiana. Our Space Yoke is FEA-tested and proven on the trail. It is made of super strong aerospace grade 6/4 titanium and is Rolls Royce aerospace heat-treated. You can find the Space Yoke on all of our titanium mountain bikes.
What drivetrains and forks are recommended for a SLACKR?
The SLACKR is compatible with geared or singlespeed drivetrains. We can customize the bike for use with wireless or mechanical drivetrains. Our adjustable Paragon dropouts allow us to swap dropout styles for a SRAM UDH Transmission derailleur, traditional derailleur, or hangerless for a clean singlespeed setup.
Side note: in 2023, we prototyped the UDH hanger with Paragon, enabling all of our prior bikes made in the last ten years to be compatible with UDH. In your face, planned obsolescence!
For the SLACKR, we recommend 140 or 150mm travel forks. At sag, they end up very similar. We only list the geo at 150mm because why not go all the way to a Cane Creek Helm or Fox 36!? Still, some folks want a lighter-duty 140mm chassis. We recommend the Fox 34 Grip X or X2 or the Pike for those riders. We are in the process of making suspension guides for all the models.
What can I customize on the SLACKR Ti?
Our most common customizations are internal routing and finish. We can do custom geometry for fit, but with six sizes, this is rarely needed. We have many options for frame finish, from our in-house anodizing, brushed, and bead blast options to Cerakote painted frames and components. We specialize in custom complete bikes. We can also provide framesets, partial builds, and even frame only.
Will there ever be a SLACKR Steel?
Just ask us for it, and we will make it happen. We don't plan to offer it as a stock model because we think Titanium is optimal for this bike, but steel is real. We get it. Stock sizes only.
The frame anodizing and brand positioning are slick. What can you tell us about that?
Thanks. We've invested a lot of studio time, testing methods, and ideas to grow our capabilities with in-house finishing. It has been one of my most significant projects in the last few years. I hand finish and perform the anodizing on each titanium frame myself. We've developed a top-notch custom finish that pops, shines, and is durable.
We have an excellent local partner, Highpoint Powder Coating, for our Cerakote paint. We can do some really cool stuff with our anodized titanium and then Cerakote-paint sections of the bikes. That is a fun way to introduce more color into the project.
That head badge is pretty. Is that a new thing?
We've had a few versions of it. Lately, we've been anodizing behind it! They fit on our steel frames as well. Each stainless steel head badge is laser cut, rolled in-house, and brushed to an attractive finish.
What music pairs with the SLACKR Ti?
The big hit capacity of The Sword meets the smoothness of Khruangbin ;)
