The Unknown Bass-X Black is a versatile urban fixed gear and single speed complete bike — freewheel included — meticulously built for riders who demand comfort and style for daily city life. Unlike aggressive track frames, the Bass-X features a relaxed frame geometry designed specifically for a smoother, more upright commuting experience without sacrificing high-speed urban performance.
This Signature Edition arrives in a sleek black-and-white colourway, delivering an understated, clean aesthetic that fits perfectly in any modern city environment. Every detail is engineered for durability, from the hardened 6066-T6 aluminum frame to the specialized urban components that make this bike a true street-ready daily driver.
Elite Performance Components
⚡The Full 12K Carbon Fork doesn't just look premium—it absorbs road vibration for sharp, confident steering, providing a massive performance upgrade over standard alloy forks.
🏯Experience ultra-smooth rolling with the Sealed-Bearing Mushroom Hubs (equipped with precision Japanese bearings) and a track-tuned 46t/17t gearing designed for efficient power transfer in the city.
🚀Premium Build
Hardened 6066-T6 Aluminum.
Full 12K Carbon Fork.
Ultra-light 8kg Setup.
Combined Value (€75)
Includes Free Pedals,
Foot Straps, and
Freewheel Cog.
Flip-Flop Freedom
Its flip-flop rear hub lets you switch between fixed gear riding and a freewheeling single-speed setup. The freewheel cog is included, so you can ride single speed straight out of the box.
Born from the underground track scene, Unknown Bikes bridges high-performance track engineering with street-level energy. We focus on the essentials: high-grade materials and minimalist aesthetics. We don't do fluff; we do fast.
Full Component Specifications
| Frame | Unknown Bass-X, Hardened 6066-T6 Aluminum |
| Fork | Unknown Full 12K Carbon, 30mm rake, 1 1/8" |
| Headset | Integrated Unknown, Sealed Bearing, 45x45st., 1 1/8" |
| Stem & Bars | Unknown 90mm Stem / Compact 420mm Drop Bars |
| Brakes | Unknown Full Brake Set / ZST Single Speed Levers |
| Drivetrain | 165mm Crank (46t) / KMC Z510 Chain / 17t Rear Cog + Freewheel |
| Bottom Bracket | 68x103mm, BSA, Square Taper |
| Wheelset | 28d Rims / Mushroom Sealed Bearing Fix-Free Hubs |
| Tires & Post | 23c Urban Tires / Unknown 27.2mm Offset Seatpost |
| Weight | Approx. 8.0kg (Size M) |
📏 Find Your Fit
Small (52cm) 160cm - 172cm Medium (55cm) 170cm - 182cm Large (58cm) 180cm - 192cm*Recommendation: If you are between sizes, we recommend sizing down for a more agile urban ride.
Also available in Bass-X White. Explore the full range of Unknown fixed gear and single speed bikes.