Beautiful Bicycle - Jobo's Custom SCOTT Spark ST

Joseph's Custom SCOTT Spark ST

Written by Joseph Bonacci, on March 27, 2024

It’s no secret (anymore) that Utah has some of the finest trail riding in the world. The Wasatch Front is rich with everything from technical single track, to fast and flowy XC rollers, to full-pucker enduro descents. Selecting and setting up a single bike to cover all these bases is a bit of a puzzle, but it can be done! I recently went about this undertaking with my SCOTT Spark ST. 

The goal for this build was to come up with a bike build that would be able to rocket up climbs and be able to handle pushing the limit on the descents, while remaining enjoyable for everything in between. Luckily, there are several great options in the short-to-mid travel MTB world and I decided the SCOTT Spark ST would be the way to go for a Utah-focused, do-it-all custom build. With customization in mind, I started out with the Spark ST 910 and went from there. So far, the bike has definitely exceeded my expectations and has been amazing overall. Here’s how the build came together…

The Build

My build centers around the SCOTT Spark ST frameset. The ST frame takes the HMF level, full carbon Spark RC frame and adapts the shock area to allow for use of the FOX Float X Factory shock inside the frame. To preserve the clean, integrated design of the Spark's front end, you need to employ a Syncros one piece bar/stem. My favorite bar happens to be the Syncros Fraser IC SL bar/stem combo, so in my case this was a fortunate necessity. With overall performance being the priority of this build, I decided to swap the 140mm FOX 34 Performance fork for the 120mm Manitou Mattoc Pro fork. Using the Manitou fork for this build increases lateral stiffness and damping, and you can easily change between 120, 130, 140, and 150mm travel options. That made it an easy choice for a high-end, versatile fork that also matches the silver and black color theme I wanted.

One of the main reasons to opt for the Spark 910 for my custom build was to use the SRAM GX Transmission drivetrain. The ability to shift under load and the Transmission's ultra-durable rear derailleur shell stand out as features that make Transmission the perfect drivetrain for this bike. Transmission's benefits are most noticeable on short punchy sections of the trail, as you can hit the AXS shift paddle whenever you need, rather than having to consciously plan out when to shift. Perfect shifts happen pretty much any time. Because of the durability, reliability and consistent performance of the Transmission drivetrain, I've been ecstatic about it overall. For brakes, I decided to try out the four-piston SRAM Level Ultimate Stealth setup. These Levels paired with 180mm SRAM HS2 rotors deliver the maximum performance possible out of the brakes, providing confidence on the descents when riding fast and loose. SRAM’s Stealth lever configuration keeps the hose as close to the handlebar as possible, which benefits bikes with integrated headset routing. This also keeps the cockpit as clean as possible and lowers the risk of ripping a hose. 

The SRAM theme of the bike continues with a RockShox Reverb AXS dropper post. I went with a shorter, 125mm-drop post so that I can get the saddle right at my knees when dropped for the descents; the stock 150mm dropper lets the saddle drop too far out of the way for maximum stability on the downs. To keep a super clean cockpit, I use a "Kate Courtney-style" SRAM blip button setup for the AXS dropper post instead of the stock AXS switch. This keeps the dropper actuation out of the way for the SCOTT Trac-loc suspension lockout lever. In the wheel department, the bike sticks with the stock Syncros Silverton 2.5 alloy wheels. My plan is to eventually swap them out for a carbon wheelset. For the time being however, they're performing as a solid wheelset that can take lots of hard riding, but I would love the added compliance that comes with carbon rims. I have the Silverton 2.5's mounted with Schwalbe Wicked Will tires. I wanted to use a faster rolling tire than the Maxxis Dissectors that come with the stock Spark 910 build. 

Given that a bike's rear wheel takes a lot of impacts and abuse, it's more prone to tubeless burps and pressure loss. With this in mind, I installed a Vittoria Air-Liner Light XC + Trail tire liner in the rear tire. I don't feel that a liner or insert is as crucial up front, so I stuck with a standard tubeless setup for the front wheel.

To keep the Transmission drivetrain running smooth, I use Ceramic Speed UFO Drip Chain lube. The wax properties of this particular lube keep the chain free of gunk and clear of dust, and I don’t think I'll ever go back to using anything else!

Bike saddles can be one of the most personal of equipment choices when outfitting your build, and my saddle of choice is the Pro Stealth in 142mm has reliably worked best for me.

The Ride

Like most custom builds, this Spark ST looks great on paper. The planning and coming together are part of the fun of building a bike from scratch, but the most important part is how it rides and performs for the rider. 

I'm happy to report that any ride on this Spark makes me believe that all of the selected parts and upgrades were more than worth the effort! Even on the first ride out on the trail, I was surprised by how capable this Spark is. One of my favorite local trails is the Red Butte Enduro. On its first run down, the bike shot over the trail's loose rocks and ruts without any difficulty. The Spark's low center of gravity from the internal shock paired with the FOX Float X2 gives the bike travel even beyond what’s spec'd by FOX. The suspension eats up big roots, rocks, and drops without too much struggle.   

The Spark ST isn’t just good in technical sections though, it also excels over jump lines. The bike feels like it wants to jump and it's easy to pop it over the jump lip, and have a stable platform for landing. The Spark keeps high traction throughout corners and doesn’t wants to slide. This bike definitely keeps your confidence high on any ascents and descents that you are likely to encounter. On the climbs, the Tracloc suspension lockout along with the GX Transmission drivetrain enable the bike to crawl up just about anything. Being able to shift under load makes it possible to grab a gear (or more) on the steepest slopes at low cadence and high power. Shifting a Transmission setup is a night and day difference from the previous generation of SRAM Eagle AXS. The shifting consistency is especially noticeable over rough terrain, where most drivetrains are sometimes prone to chain drop. One of the features SRAM lists with Transmission is that the chain will consistently stay on and not drop, even while shifting. 

So far, this Spark ST has been a ton of fun on all different types of trails. It's confident enough to rip through technical terrain, playful enough to have fun on flow trails, and fast enough to tackle cross-country-style rides. As a one-bike-quiver bike for Utah, this custom Spark has exceeded my expectations and I'm looking forward to taking it more places to ride and to continue to find its limits. The SCOTT Spark ST could not be a better bike for Utah riding and I'm stoked with this custom build! We are happy to help you find the perfect bike for what you want to ride, and spec it out however you'd like. Give us a call or visit us in person to discuss your next bike, or how we can improve your trusted trail weapon!


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