Gustav Gullholm, aka Dangerholm, has been crafting some of the most unique and lightweight bike builds for over a decade. The Swedish custom bike builder is known for his one-off creations, refinishing and speccing out bikes with carefully curated selections of some of the lightest, most exotic and most expensive components on the market. Ten years after turning his first Scott Spark RC into the worlds lightest 29 full suspension mountain bike, Dangerholm has a new ultralight build on the latest version of Scotts XC race platform.Over the years, Dangerholm has built numerous Scott Spark RC bikes, including 3rd- and 4th-generation frames. But Dangerholm says the 5th-generation Spark raises the bar for XC even higher with its suspension performance, geometry, and light weight. So, he set out with the goal of turning the latest Spark RC frame into a sub-9kg complete build that was not only light, but also fast, fun to ride, and pleasing to the eye, too.I started with setting 9kg / 19.84lbs as a weight goal for the complete bike. Partially as a fun challenge, but also since I personally find that it is around this weight and below that you truly start to notice a big difference and really feel that youre riding a superlight bike. With the low frame weight and lightweight components available today, this is a relatively easy weight target as far as tuning goes, but the real challenge lies in getting there without compromising performance or durability.-DangerholmScott Spark RC FrameAccording to Dangerholm, the latest version of the Scott Spark RC has a huge focus on user-friendliness, which already comes served on a silver platter from the engineers and designers at Scott. He says that overall this bike build was relatively straightforward, with little complexity or major modifications to the frame.That said, he took the time to strip the frame down to a custom-polished high-gloss raw carbon fiber finish. He also created matching transparent covers for the unique internally mounted rear shock placement on the Spark RC frame. This even includes a cutout for the Flight Attendant motor/battery pack on the RockShox SIDLUXE shock.SuspensionOn the topic of Flight Attendant, its impressive to see it included on both the rear shock and the fork. The Flight Attendants battery and electronics add both complexity and weight, a trade-off that Dangerholm is apparently willing to accept for its performance advantages.Interestingly, the Intend Samurai XC fork with the Flight Attendant Cartridge is almost identical to the claimed weight of the RockShox SID Ultimate Flight Attendant fork at 1,624 grams. Not only that, but the Intend fork allows for the polished silver look, which is an aesthetic/theme shared with many of the other components on the build.ComponentsGiven his experience putting together lightweight bike builds, it seems that Dangerholm has a direct line to all of the most exotic component manufacturers in the business. While many of these are more obvious, like wheels, brakes, cranks, etc, its the little things that show that Dangerholm goes all in on his lightweight builds.Take, for example, the RadoxX Components Oknytt Dangerholm Signature topcap that weighs just 3.2g, or the Extralite UltraStar 5 Expander, which weighs 4.6g. He also chose ExtraLite ExtraBolt hardware for the brakes and bottle cage, Oak Components ti bolts for the power meter, and 7g Tune valves for the wheels.Of course, Dangerholm doesnt mess around when it comes to the more visually obvious components, either. Starting with the drivetrain, the WERT Titanium cranks are a thing of beauty, especially with a silver 38T Garbaruk chainring. The special edition SRAM 1987 chain and cassette add to the shiny silver theme, while the HOPP Carbon tuning kit on the GX AXS derailleur brings its weight down to 357.7g.Moving to the wheels, the PI ROPE Light SLS5 285 wheelset is not a common sight. With textile spokes and carbon rims, these wheels weigh in at a claimed 949.1g for the pair (plus 19g for the valves and rim tape). Those are wrapped in TUFO XC11 + XC14 TR SG 292.35 tires. Speed control duties are tasked to a set of Trickstuff Piccola brakes with prototype titanium levers paired with Carbon-Ti X-Rotor SteelCarbon 3 rotors. Its certainly not every day you see carbon fiber on MTB brake rotors.Moving to the cockpit, Darimo is an obvious choice for lightweight carbon handlebars and stems. The ExtraLite HyperGrips and HyperPlugs reportedly weigh just 9.1g, and the Zirbel ZShift01 and SRAM BlipBox help to keep the cockpit clean and AXS Pod-free. The Vertical Helium Race 120mm dropper and Ignitor Control remote are also among, if not the lightest on the market. Lighter still is the Berk Composites prototype saddle that weighs a scant 61.3g!Dangerholms Scott Spark RC: Spec ListFrame: Scott Spark RC HMX-SL size L 1446,6gFork: Intend Samurai XC 120mm with RockShox Flight Attendant cartridge 1624,5gRear shock: RockShox SIDLuxe Flight Attendant 352,7gHeadset: Syncros with CeramicSpeed SLT bearings 106,0gSpacers: Onyx Racing Products 3,2gTopcap: RadoxX Components Oknytt Dangerholm Signature 3,2gExpander: Extralite UltraStar 4 4,6gStem: Darimo IX2AL 80mm -12 76,4g(Darimo computer mount- 3,7g)Handlebar: Darimo MTB Flatbar 690mm 6 custom polished 102,2gGrips: Extralite HyperGrips with Extralite HyperPlugs 9,1gController: Zirbel ZShift01 with SRAM BlipBox 62,8gBrakes: Trickstuff Piccola with prototype titanium levers 337,8g(Extralite ExtraBolt 4.5 + 9.1 19,6g)Rotors: Carbon-Ti X-Rotor SteelCarbon 3 160+180mm 175,3gRear derailleur: SRAM GX with full HOPP Carbon tuning kit 357,7gCassette: SRAM Eagle Transmission 1987 316,4gChain: SRAM Eagle Transmission 1987 250,5gChainring: Garbaruk MTB Thread Mount 38T 54,8gPowermeter: SRAM XX SL 107,2g(Oak Components titanium bolts 4,5g)Cranks: WERT StW-M 175mm titanium 321,6gBottom bracket: CeramicSpeed BB ALPHA 68,2Pedals: Xpedo M-Force 8 Ti 213,4gWheels: PI ROPE Light SLS5 285 949,1g(Tune valves- 7,0g, Orange Seal tim tape 12,0g)Tires: TUFO XC11 + XC14 TR SG 292,35 1266,0g(Milkit sealant- 196,4g)Seat post: Vertical Helium Race 120mm customized 334,6g(Vertical Ignitor Control customized 21,5g)Saddle: Berk Composites prototype 61,3gBottle cage: Syncros Tailor Cage 1.0 with Extralite ExtraBolt 12.1 screws 24,2gTotal weight: 8987,8g (8,99kg / 19.82lbs)Not only is this Scott Spark RC a very lightweight and elegant-looking bike with an exotic build, but Dangerholm says, The end result is the best bike Ive ever had.You can keep up with Gustav Gullholm and all of his custom bike creations on Instagram, @dangerholm.