Hyosung SF 50 [2004-2010]: A Retrospective Review of the Plucky Urban Commuter
Introduction
The Hyosung SF 50, produced between 2004 and 2010, is a scooter that embodies simplicity and practicality in the 50cc class. Designed for urban commuters, students, and first-time riders, this lightweight two-stroke machine offers a no-frills approach to city mobility. While it lacks the polish of its Japanese or European counterparts, the SF 50 carves out a niche as an affordable, easy-to-maintain workhorse. After spending a week weaving through traffic and navigating cramped parking spots, it’s clear this scooter deserves a closer look for those prioritizing function over flair.
Design & Ergonomics
The SF 50’s design is quintessentially early-2000s scooter—angular body panels, a stepped seat, and a utilitarian dashboard. At 1,780 mm (70.1 inches) long and 88 kg (194 lbs) dry weight, it feels compact yet sturdy. The 740 mm (29.1-inch) seat height accommodates shorter riders effortlessly, though taller riders might find the legroom cramped during longer rides.
Color options varied by year and trim, with bold choices like Racing Yellow, Sonic Blue, and Fiery Red adding personality. The SF 50 Racing models leaned into sporty aesthetics with racing decals and contrasting trim, though build quality shows its budget roots. Plastic panels fit loosely, and the switchgear feels basic, but the steel frame underneath inspires confidence.
Storage is minimal—a shallow under-seat compartment fits a half-face helmet at best. The 4.3–4.8-liter (1.14–1.27 US gal) fuel tank is accessible under the seat, emphasizing the scooter’s "grab-and-go" philosophy.
Engine & Performance
At its heart lies a 49cc single-cylinder two-stroke engine, air-cooled and carbureted. Output varies between models:
- Base SF 50/Rush 50: 6.5 HP (4.7 kW) @ 6,000 RPM
- SF 50 Racing: Detuned to 3.5 HP (2.6 kW) @ 6,800 RPM for regulatory compliance in certain markets
The engine’s character is unmistakably two-stroke: buzzy, smoky, and eager to rev. Throttle response is abrupt at low RPMs, requiring a gentle hand to avoid jerky starts. Once moving, the automatic CVT transmission (final drive via belt) delivers smooth acceleration up to a governed top speed of 45 km/h (28 mph). It’s peppy enough for city traffic but struggles on hills—a full-throttle climb might see speeds drop to 30 km/h (18.6 mph).
The two-stroke’s quirks shine here. Cold starts demand patience, even with the electric/kick combo starter. Fuel mixing is mandatory (1L of 2T oil per tank), and the VM14 carburetor needs occasional tuning. Yet, there’s charm in its raw mechanical feedback—a stark contrast to today’s sterile four-strokes.
Ride Experience
Riding the SF 50 feels like piloting a hyperactive moped. The 12-inch wheels and short 1,270 mm (50-inch) wheelbase make it nimble in traffic, though stability wavers above 40 km/h (25 mph). The telescopic front fork and rear swingarm suspension offer 75 mm (3 inches) and 65 mm (2.6 inches) of travel, respectively—adequate for smooth roads but harsh over potholes.
Braking is a mixed bag. The front 220 mm disc brake provides decent bite, but the rear drum lacks urgency. Combined stops from 50 km/h (31 mph) require planning, especially in wet conditions. Tires vary by model:
- Standard: 110/70-12 (front), 120/90-12 (rear)
- Racing: 120/90-10 (front), 130/90-10 (rear)
The Racing’s wider tires add grip during aggressive cornering, but the SF 50 isn’t a canyon carver. Vibration through the bars and floorboard is pronounced at peak RPM, reminding you this is a budget commuter first.
Competition
In the 50cc scooter segment, the SF 50 faced fierce rivals:
- Honda Vision 50: A four-stroke counterpart with superior refinement and 60+ mpg efficiency but lower peak power.
- Aprilia SR 50: A premium option with liquid cooling, sporty styling, and double the price tag.
- Yamaha Aerox 50: Known for its water-cooled engine and tuner-friendly design, appealing to modders.
The Hyosung’s edge lies in simplicity. Unlike the Vision’s anemic four-stroke or the Aerox’s complex liquid cooling, the SF 50’s two-stroke engine is easier (and cheaper) to rebuild. However, it falls short in emissions compliance and long-term durability—expect more frequent top-end rebuilds compared to four-strokes.
Maintenance
The SF 50 rewards hands-on owners. Key considerations:
1. Engine Care:
- Oil Mixing: Use high-quality 2T oil at a 50:1 ratio.
- Spark Plugs: NGK BR8HSA or BR8HIX, gapped to 0.6 mm. Replace every 3,000 km (1,864 miles).
- Carb Cleaning: The VM14 carburetor clogs easily. Clean annually or after prolonged storage.
- Transmission:
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Inspect the drive belt every 5,000 km (3,107 miles). Cracking or fraying demands immediate replacement.
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Brakes:
- Fluid: DOT 4, changed every two years.
-
Pads: The front disc wears faster under heavy use.
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Tires:
- Opt for grippy aftermarket rubber like Michelin City Grip for wet-weather confidence.
MOTOPARTS.store stocks OEM-spec parts and upgrades, from performance air filters to reinforced drive belts. For Racing models, consider a free-flow exhaust to unlock restricted power—just expect louder operation.
Conclusion
The Hyosung SF 50 isn’t perfect, but it’s honest. It’s a scooter that asks little and gives just enough—perfect for short commutes, college campuses, or as a learner machine. While rivals outclass it in refinement, the SF 50’s mechanical simplicity and low running costs make it a compelling choice for DIY enthusiasts. Just keep a toolkit handy, and this plucky two-stroke will keep ticking.
Whether you’re refreshing an old SF 50 or optimizing your daily rider, MOTOPARTS.store has the components to keep your Hyosung running smoothly—or turn it into a pocket-sized project bike with a personality as bold as its Racing Yellow paint.
Specifications sheet
Engine | |
---|---|
Stroke: | Two-stroke |
Max power: | 4 kW | 5.0 hp |
Fuel system: | Carburettor (VM 14) |
Max power @: | 6800 rpm |
Displacement: | 49 ccm |
Bore x stroke: | 41.0 x 37.7 mm (1.6 x 1.5 in) |
Configuration: | Single |
Cooling system: | Air |
Compression ratio: | 7.2:1 |
Number of cylinders: | 1 |
Dimensions | |
---|---|
Wheelbase: | 1270 mm (50.0 in) |
Dry weight: | 88 |
Wet weight: | 95 |
Seat height: | 740 mm (29.1 in) |
Overall width: | 662 mm (26.1 in) |
Overall height: | 1110 mm (43.7 in) |
Overall length: | 1825 mm (71.9 in) |
Ground clearance: | 125 mm (4.9 in) |
Fuel tank capacity: | 4.8 L (1.27 US gal) |
Drivetrain | |
---|---|
Final drive: | belt |
Transmission: | Automatic |
Maintenance | |
---|---|
Rear tire: | 120/90-12 |
Engine oil: | 2-stroke oil |
Front tire: | 110/70-12 |
Break fluid: | DOT 4 |
Spark plugs: | NGK BR8HSA or NGK BR8HIX |
Spark plug gap: | 0.6 |
Engine oil capacity: | 1.0 |
Final drive oil capacity: | 0.11 |
Chassis and Suspension | |
---|---|
Frame: | Steel |
Rear brakes: | Drum brake |
Front brakes: | Single disc |
Rear suspension: | Swingarm |
Front suspension: | Telescopic fork |
Rear wheel travel: | 65 mm (2.6 in) |
Front wheel travel: | 75 mm (3.0 in) |