Gustav Gulholm, aka Dangerholm, is back with another drool-worthy dream build. This time, it’s the 9.19 kg Scott Spark RC Hypersonic. We got eyes on this at Eurobike last month, where Dangerholm himself talked us through the build process, and how he painstakingly went about selecting lightweight, but functionally appropriate parts for this 120mm travel downcountry rig. The lighting was really poor, doing the hybrid carbon-pink paint job a great disservice, so we waited until now to show you the entirely of the bike in all its glory.
“The plan for this bike was to build a modern cross-country bike with all the new important features such as a capable frame and suspension, dropper seat post and 2.4″ tires but at an old-school low weight. Quick and responsive on the climbs, fast and fun on the descents. In short – the best of two worlds” – Dangerholm
Dangerholm’s Scott Spark RC Hypersonic
A Scott Spark RC sits at the heart of this Hypersonic dream build, a HMX carbon frameset that weighs just 1956g to begin with. That includes the RockShox Nude 3-Position Shock that is hidden inside the seat tube, driven by the linkage-driven single-pivot.
A highlight of the Hypersonic is the Intend Samurai XC fork. It is one of the lightest 120mm travel forks in the World, weighing a claimed 1,495g. The one on Dangerholm’s bike has an aluminum steerer tube, but there is a CC version with a carbon steerer tube that weighs an incredible 1,385g.
Dangerholm opted to run Trickstuff Piccola brakes with the carbon levers. They operate flat-mount Trickstuff C22 calipers clamping Trickstuff Dächle UL rotors – 180mm front, 160mm rear. The discs are fastened with Kogel titanium bolts and the calipers use titanium bolts as well.
The Hypersonic is home to a prototype crankset from Garbaruk, with 175mm crank arms and a 40T chainring. This is their XC Crankset which will retail at $420 USD, available from September 1st. It weighs just 384g for the crank arms and spindle, just 20g heavier then SRAM’s Carbon XX1 DUB cranks.
Making up the rest of the drivetrain is an assortment of parts from SRAM, Kogel and ROTOR.
A SRAM Eagle XX1 derailleur shifts the SRAM chain through a ROTOR 11-46t cassette. It’s not just any Eagle XX1 derailleur, though; Dangerholm has customized it with custom carbon parts from Hopp Components, and replaced the stock cage with a Kogel Kolossus OSPW.
The blinged-out custom drivetrain drives a 1039g custom-built wheelset built up using an Italian-made Extralite HyperBoost 3 hubset, with Radsporttechnik Muller MXCR rims (280g each) laced with steel Sapim CX Super spokes. Seated to the rims are Pirelli XC RC Lite 29″ x 2.4″ tires, set up tubeless with Syncros Eco Sealant and Radsporttechnik Muller tubeless valves.
The Hypersonic’s cockpit is home to the Syncros Fraser iC SL carbon handlebar-stem combo cut to 730mm wide, with a 90mm length. It has a -30° drop. It integrates perfectly into the frame using specific spacers and covers, and with different bearing cups you can adjust the head angle. On this build, Dangerholm is running the neutral 0° cups.
Gustav is also saving weigh at the headset with lighter bearings. He is using an Extralite UltraStar 4 Expander weighing just 4.5g, as well as an Extralite UltraBottom 51-52 lower bearing and bearing race.
Dangerholm has the rear shock hooked up to a custom lock-out remote that also incorporates the lever for the Yep Components Podio 80mm dropper seat post. The custom three-lever remote is made from a combination of the 2017 RideLoc remote and a 2022 TwinLoc remote. It saves 20.6 g as compared to the stock version and is Matchmaker compatible to run with the Trickstuff Piccola brake with carbon lever. Gustav says it is quick work to remove the rear shock half-way or even fully to get access to the remote cable. The big opening in the down tube allowed him to install the remote cable with the rear shock still in position.
The Yep Podio is clamped by an Intend Corona seat post clamp. Atop it is a stripped-down carbon Tune Speedneedle saddle.
“At just 9,19kg / 20,26lbs including pedals it’s not the lightest mountain bike in the world but I’d say that it definitely meets my goals of a modern capable cross-country bike at a low weight rarely seen these days” – Dangerholm.
For more incredible dream builds from Dangerholm, you can follow his exploits on Instagram @dangerholm.
