30-Year Arcs / A1-Licence / Aprilia RS 125 Lineage
Aprilia Italy

Aprilia RS 125. From 2-stroke legend to modern 4-stroke supersport.

The Aprilia RS 125 is the longest-running 125cc supersport nameplate — and one of the few bikes on this site whose 1996 and 2006 versions were genuinely better at being a sport bike than the modern equivalent. The 2-stroke RS125 (1992-2010) was a 33bhp pocket-rocket; the modern 4-stroke RS 125 (2010-on) is A1-licence compliant at 14.7bhp. Different beast, same name. £5,300 OTR for 2026. Aprilia kept the RS 125 nameplate alive when most rivals didn't.

1996
RS125 (2-stroke, legend era)
2006
RS125 (2-stroke, end of era)
2016
RS4 125 (4-stroke transition)
2026
RS 125 (current 4-stroke)
Continual audits are underway to verify local pricing for every bike in every market. Apologies for any gaps you see while this is in progress.
1996 RS125 (2-stroke, Rotax 122 era)
1996 Aprilia RS125 two-stroke

Aprilia RS125 (2-stroke)

Rotax-built 125cc 2-stroke, 33bhp peak
Genuine Moto3 / GP125 race-bike aesthetic, no licence restriction yet

125cc liquid-cooled 2-stroke single
33 bhp
23
118
805
Rotax 122 2-stroke engineAluminium twin-spar frameUSD forks (most years)Brembo brakes6-speed gearboxABSFuel injection (carb-fed)Catalytic converterModern emissions complianceLiquid-cooledRace-replica fairings
Known issues
  • 33bhp WAS the headline — but pre-1996 UK A1 cap was 14.5bhp; restricted RS125s were the norm
  • 2-stroke smoke + smell — kerbside-banned in many cities now
  • Engine top-end every 10-15k miles (rebuild ~£800)
  • Carburettor jetting demanding for cold UK starts
  • Used parts now scarce; OEM Rotax pistons hard to source
£3,295
~£6,800
£4-7k+
2006 RS125 (2-stroke, end-of-life)
2006 Aprilia RS125 two-stroke late

Aprilia RS125 (2-stroke)

End-of-life for the 2-stroke RS125
Last 2-stroke road bikes before Euro 3 killed them

125cc liquid-cooled 2-stroke single
33 bhp
23
121
805
Rotax 122 2-stroke engineAluminium twin-spar frameUSD forksBrembo brakes6-speed gearboxRace-replica fairingsLiquid-cooledABSFuel injectionCatalytic converterEuro 3 compliance from 2007
Known issues
  • 2-strokes phased out by Euro 3 emissions (2007+)
  • Engine top-end every 10-15k miles
  • Hard to find specialists who'll work on 2-strokes today
  • Carb-fed in cold weather is fiddly
  • Insurance for under-25s often punitive
£4,099
~£7,250
£3.5-5.5k
2016 RS4 125 (4-stroke, transition era)
2016 Aprilia RS4 125 four-stroke

Aprilia RS4 125

4-stroke replacement for the 2-stroke RS125
Built by Piaggio Group, Asian-supplied engine

125cc liquid-cooled 4-stroke single
14.5 bhp
10.9
138
820
4-stroke 125cc singleAluminium twin-spar frameUSD forksABS standardRace-replica fairingsFuel injectionLiquid-cooledLCD dashHalogen lightingSlip/assist clutchQuickshifterTraction control
Known issues
  • Felt slow vs the 33bhp 2-stroke ancestor
  • Aprilia UK dealer network thin
  • Build quality less polished than Honda/Yamaha
  • No quickshifter or modern aids
  • Tank only 14L — ~280 mile range
£4,599
~£6,300
£2.4-3.8k
2026 Current · RS 125 (4-stroke)
2026 Aprilia RS 125 four-stroke

Aprilia RS 125

2021 redesign: full LED, TFT, ride-by-wire
Race-replica RSV4-inspired styling

125cc liquid-cooled 4-stroke DOHC single
14.7 bhp
10.7
140
820
Aluminium twin-spar frameUSD forksDual-channel ABSSlip/assist clutchQuickshifter (Tuono GP option)Multi-function LCD dashFull LED lightingFuel injectionRace-replica fairingsTraction control (option)Aprilia race styling cuesA1-licence compliantUSB charge
Known issues
  • Heaviest 125 supersport (140kg vs CBR125R 137kg)
  • Aprilia UK dealer network thin
  • Build quality less polished than Japanese rivals
  • Tank 14L — ~260 mile range
  • Service intervals 4,500 miles, Aprilia prices
  • Otherwise the most stylish 4-stroke A1 supersport
£5,300
Yamaha YZF-R125 £5,501
RS 125
// 30-Year Delta

What actually changed.

1996 → 2026 · 30 years of "progress"
RS125 nameplate has been around since 1992 33+ years continuous The Aprilia RS 125 nameplate has been on continuous sale (with brief gap during 2-stroke phase-out) since 1992 — making it one of the longest-running 125cc supersport nameplates in motorcycling. Yamaha R125 launched 2008, Honda CBR125R from 2004, Suzuki GSX-R125 from 2017. The Aprilia is the original.
2-stroke → 4-stroke = different bike 33bhp → 14.7bhp The 2-stroke RS125 (1992-2010) made up to 33bhp from a Rotax 122 engine — though pre-1996 UK A1 licences capped it at 14.5bhp. After Euro 3 emissions banned 2-strokes in 2007, Aprilia rebooted with a 4-stroke 14.5-14.7bhp version (2010-on). Same name, completely different motorcycle. The 2-stroke is a kart with fairings; the 4-stroke is a learner sport-bike.
Why the 2-stroke disappeared Euro 3 emissions (2007) Euro 3 emissions standards (2007 mandatory for new motorcycles) effectively banned 2-stroke road bikes — they couldn't meet HC and CO limits without losing performance. Aprilia, Yamaha, Honda, Suzuki all dropped their 2-stroke 125s in 2006-2008. Aprilia's 4-stroke replacement was the slowest-feeling A1 sport-bike most riders had experienced — power dropped from 33bhp to 14.5bhp.
Used 2-stroke RS125 = collector item £4-7k for mint 90s/00s bikes Mint 1990s-2000s 2-stroke RS125s now command £4,000-£7,000+ in collector condition. Significantly more than they cost new, even after inflation adjustment. Reasons: nostalgia for 2-stroke era, rarity of unrestored examples, steady decline in good donors. Realistic running costs (top-end every 10-15k miles, 2-stroke oil, jetting) mean these are toys — not commuters.
4-stroke build location Piaggio Group + Asian supply Modern RS 125 is built within the Piaggio Group (Aprilia is owned by Piaggio since 2004). Engine assembly is partially Asian-sourced (Vietnam factory). Final assembly in Italy. Build quality has improved through the 4-stroke generations but remains less polished than the Japanese rivals (Honda CBR125R, Yamaha R125).
RSV4-inspired styling Aprilia race DNA The 2021 RS 125 redesign brought styling cues from the £20k+ Aprilia RSV4 superbike — three-LED face design, sharp tail unit, twin-element fairing. Visually this is the most race-replica A1 sportbike on UK sale. Even rivals concede the RS 125 'looks the part' more convincingly than the R125 or CBR125R.
Why riders still buy the 4-stroke RS Italian flair vs Japanese precision RS 125 sells worse than the Yamaha R125 or KTM RC 125 in the UK — but has a loyal customer base. Reasons: best-in-class styling, Aprilia race heritage, distinctive Italian feel. Trade-offs: thinner dealer network, higher service costs, slightly less polished build. For buyers who'd rather have a slightly imperfect Aprilia than a perfectly competent Honda.
// Sources

Where these numbers come from

Every figure on this page is from a published manufacturer spec sheet or a reputable review publication. No press junkets, no opinions in the spec data. Inflation calculated using Bank of England's CPI tool.

1996 RS125 2-stroke Aprilia heritage · MCN archive · Bennetts BikeSocial
2006 RS125 2-stroke Aprilia Europe · MCN archive · Visordown
2016 RS4 125 Piaggio Group · MCN review · Bennetts
2026 RS 125 4-stroke Aprilia UK · MCN · Bennetts BikeSocial