By NastyNils·
Motorcycle comparison · Supersport
Aprilia RS4 125 (MY2011) vs KTM RC 125 (MY2025)
Aprilia RS4 125 vs KTM RC 125: which one to buy for the riding you do.
Turn the Aprilia RS4 125 into a bend and it's already tracking the line you picked, with nothing left to correct. The KTM RC 125 flicks in off a fingertip nudge.
What makes each one tick
RS4 125
The throttle wakes a single that's happiest spinning high in the revs. Its Italian bodywork looks the part.
RC 125
A light trellis frame and taut suspension let the RC 125 change direction through city traffic in a heartbeat. Between the brake lever and the next apex, there's barely a pause before it's pointed somewhere new. Its engine won't hand over full power until you hold the revs high and commit. The trellis frame lives for corners.
The Voice of Experience
What actually separates them
- The RS4 125 has the larger fuel tank: 3.8 US gal (14.5 L) vs 3.6 US gal (13.7 L).
- ABS: standard on the RC 125, not offered on the RS4 125.
- TFT Display: standard on the RC 125, not offered on the RS4 125.
Which one for the way you ride
There's no real gap on commuting, twisty roads, running costs, and a first bike. Sit on both and let fit and price decide.
Who each one is built for
What's good, and what you'll live with
RS4 125
What owners say
Strengths
- Top-tier sport bike
RC 125
What owners say
Strengths
- Sharp, agile handling
- Striking MotoGP-inspired styling
Known problems to check before you buy
RS4 125
- Fuel pump reliability issues Fuel pump failures have been reported, which can cause loss of fuel pressure, hesitation under acceleration, or engine stalling.
RC 125
No confirmed faults on file yet. That's not the same as fault-free.
What they share
- Displacement
- 125 cc
- Engine
- Single-cylinder
- Cooling
- Liquid-cooled
- Power
- 15 hp (11 kW)
- Gearbox
- 6-speed
- Final drive
- Chain
Where the spec sheets split
| RS4 125 | RC 125 | |
|---|---|---|
| Seat height | 31.9 in (810 mm) | 32.4 in (824 mm) |
| RS4 125 | RC 125 | |
|---|---|---|
| Torque | 8 lb-ft (11 Nm) | 8 lb-ft (12 Nm) |
| RS4 125 | RC 125 | |
|---|---|---|
| Fuel capacity | 3.8 US gal (14.5 L) | 3.6 US gal (13.7 L) |
| RS4 125 | RC 125 | |
|---|---|---|
| Front tire | 100/80-17 | 110/70-17 |
| Rear tire | 130/70-17 | 150/60-17 |
What comes fitted, what costs extra
| RS4 125 | RC 125 | |
|---|---|---|
| ABS | Not offered | Standard |
| TFT Display | Not offered | Standard |
| LED Headlight | Not offered | Standard |
Head to head, area by area
Both bikes on the same scale, one area at a time.
