The Unknown SC-1 Red is a tough, reliable fixie built for everyday riding. The vibrant red finish turns heads and makes you impossible to miss on the road — a bike with serious kerb appeal. Built from 4130 chromoly steel, the SC-1 is made to handle the punishment of daily city commuting while keeping you comfortable mile after mile. At 9.4kg in size M, it is one of the lightest steel fixies in its class.
Chromoly steel is legendary for its toughness and natural flex — it soaks up road vibration better than aluminum, making every ride smoother and more forgiving on rough surfaces. The steel fork pairs perfectly with the frame for stable, confident handling in city traffic. The sealed-bearing Mushroom hub wheelset with Japanese bearings delivers reliable, friction-free rolling day in, day out.
🚀Premium Build
Hardened Unknown SC-1, 4130 chromoly steel.
Full Unknown steel fork, 30mm rake, 1 1/8".
Ultra-light 9.4kg Setup.
Combined Value
Shipped with front and rear brakes, and free pedals with foot straps worth €50 included. Plus free front and rear lights worth €20 included. Ready to ride straight out of the box.
⚙️Flip-Flop Freedom
Switch between Fixed Gear and Single Speed effortlessly. Our specialized Flip-Flop Hub gives you the best of both worlds.
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 SC-1, 4130 chromoly steel |
| Fork | Unknown steel fork, 30mm rake, 1 1/8" |
| Headset | Integrated Unknown, SB, 45x45st., 1 1/8" |
| Stem | Unknown 60mm |
| Handlebars | Unknown riser bars |
| Grip | Unknown |
| Brake levers | ZST single speed |
| Brakes | Unknown front and rear brake set |
| Chainarm | Unknown 165mm, 130BCD |
| Chainwheel | Unknown 46t, 130BCD, 1/2"x1/8" |
| Chain | KMC Z510 1/2"x1/8" |
| Rear cog | 17t |
| Rims | Unknown 28d |
| Hubs | Unknown Fix/Free flip flop 28d, SB |
| Tires | 23c |
| Seatpost | Unknown 27.2mm, 300mm, 20mm offset |
| Saddle | Unknown |
| Bottom bracket | 68x103mm, BSA, Square taper |
📏 Find Your Fit
53 155cm – 167cm 55 167cm – 178cm 59 178cm – 190cm 62 190cm – 200cm*Recommendation: If you are between sizes, we recommend sizing down for a more agile urban ride.