Unknown SC-1 Gray | 4130 Chromoly Fixie & Single Speed

Signature Urban Frame — Gray Edition

The Unknown SC-1 Gray is a tough, reliable fixie built for everyday riding. The sleek gray finish strikes the perfect balance between subtle and stylish — a refined, modern look that blends into any urban environment. Built from 4130 chromoly steel, the SC-1 is designed to handle years of daily commuting without breaking a sweat. At 9.4kg in size M, it is one of the lightest steel fixies in its class.

Built to Last

Chromoly steel is the rider's choice for frames that need to be both strong and comfortable — its natural flex absorbs road vibration, giving you a smoother ride than aluminum over uneven city streets. The steel fork delivers steady, reliable handling that inspires confidence in traffic. The sealed-bearing Mushroom hub wheelset with Japanese bearings ensures silky smooth rolling on every ride.

Ride Fixed or Single Speed

The SC-1 comes with a flip flop hub, giving you the choice to ride fixed gear or flip the rear wheel for single speed. Ideal whether you are a beginner wanting the safety of coasting, or a seasoned rider who enjoys switching between setups. The 46t/17t gearing is well suited for flat urban riding.

What's Included

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.

Weight: 9.4 kg in size M (without pedals and brakes)

*Graphics on the frame may differ slightly from photos.

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

Best Use Cases

✅ Daily urban commuting
✅ Fixed-gear / Single-speed riding
✅ First fixie for beginners
✅ Long rides with friends

Size Chart

Frame Size	Rider Height
53	155cm – 167cm
55	167cm – 178cm
59	178cm – 190cm
62	190cm – 200cm

``` ### Search Engine Listing **Page title:** ``` Unknown SC-1 Gray – 4130 Chromoly Fixie & Single Speed | EU ``` **Meta description:** ``` 🚲 The Unknown SC-1 Gray — tough 4130 chromoly steel fixie & single speed. Flip flop hub, front & rear brakes, riser bars. 9.4kg. Free pedals + free lights included ✓ Fast EU shipping ✓ ``` ### Image File Names ``` unknown-sc-1-gray-fixie-side-view.jpg ``` ``` unknown-sc-1-gray-single-speed-front-angle.jpg ``` ``` unknown-sc-1-gray-chromoly-frame-detail.jpg ``` ``` unknown-sc-1-gray-rear-wheel-flip-flop-hub.jpg ``` ``` unknown-sc-1-gray-riser-bars-headtube.jpg ``` ### Image Alt Text ``` Unknown SC-1 Gray 4130 chromoly fixie - full side view ``` ``` Unknown SC-1 Gray single speed bike - front angle view ``` ``` Unknown SC-1 Gray - chromoly steel frame detail closeup ``` ``` Unknown SC-1 Gray fixie - rear wheel and flip flop hub ``` ``` Unknown SC-1 Gray - riser bars and headtube detail