4130 Chromoly Frame
A 4130 chromoly steel frame with a steel fork (30 mm rake, 1 1/8").
Unknown SC-1
Black
Fixed Gear / Single Speed Bike
The Unknown SC-1 is built around a 4130 chromoly steel frame and a steel fork, with riser bars, front and rear brakes and a fix/free rear hub.
This version has a black frame and fork with white Unknown graphics, and black wheels, bars and saddle.
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Fix / Free Hub
Flip-flop rear hub
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46T × 17T
165 mm cranks, 130 BCD
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Riser Bars
With grips and a 60 mm stem
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Front & Rear Brakes
Fitted as standard
Key Features
Riser Bar Cockpit
Unknown riser bars with grips on a 60 mm stem, and ZST brake levers.
Saddle & Seatpost
An Unknown saddle on a 27.2 mm seatpost with a 20 mm offset.
46T × 17T Drivetrain
165 mm cranks with a 46T chainring, KMC chain and 17T cog on a fix/free rear hub.
Steel for Everyday Riding
The SC-1 pairs a 4130 chromoly steel frame with a steel fork, riser bars and a 60 mm stem, giving it a straightforward city-bike setup.
The drivetrain runs a 46T chainring and a 17T cog on a fix/free rear hub. Front and rear brakes are fitted, and pedals with foot straps and a single-speed freewheel are included.
What's Included
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Pedals + Foot Straps
Included free with this bike
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Single-Speed Freewheel
For the threaded side of the hub
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Front & Rear Brakes
Fitted as standard, with ZST levers
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90% Pre-Assembled
Final assembly required before riding
Specifications
| Frame | Unknown SC-1, 4130 chromoly steel |
|---|---|
| Fork | Unknown steel fork, 30 mm rake, 1 1/8" |
| Hubs | Unknown fix/free flip-flop, 28H |
| Chainring | Unknown 46T, 130 BCD, 1/2" × 1/8" |
| Rear cog | 17T |
| Handlebars | Unknown riser bars |
| Brakes | Unknown front and rear brake set |
| Tyres | 23c |
Show all specifications
| Headset | Unknown integrated, 45×45, 1 1/8" |
|---|---|
| Stem | Unknown 60 mm |
| Grips | Unknown Bikes grips |
| Brake levers | ZST single speed |
| Crank arms | Unknown 165 mm, 130 BCD |
| Chain | KMC Z510, 1/2" × 1/8" |
| Rims | Unknown 28H |
| Seatpost | Unknown 27.2 mm, 300 mm, 20 mm offset |
| Saddle | Unknown Bikes saddle |
| Bottom bracket | 68 × 103 mm, BSA, square taper |
Sizing
- 52156–167 cm
- 55167–178 cm
- 59178–190 cm
- 62190–200 cm
Frame sizes in the SC-1 range and recommended rider height. Size 52 is part of the range but is not currently offered: the size selector shows the sizes you can order. Between sizes? We recommend sizing down for a more agile urban ride.
Fixed Gear & Single Speed
The SC-1 has a fix/free rear hub: a 17T fixed cog on one side, and a threaded side for the single-speed freewheel, which is included. See all SC-1 colours or other fixed gear bikes.
Frequently Asked Questions
Is the Unknown SC-1 fixed gear or single speed?
Both. It has a fix/free rear hub with a 17T fixed cog on one side. A single-speed freewheel is included for the other side.
Does the SC-1 have brakes?
Yes. Front and rear brakes are fitted as standard, with ZST levers.
Are pedals included?
Yes. Pedals with foot straps are included free with the bike.
What size SC-1 do I need?
Use the sizing guide above. If you are between sizes, we recommend sizing down for a more agile urban ride.
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Free Standard Shipping
No minimum order
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5-Year Frame Warranty
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Secure Payment
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