Details of Cars

Aprilia SX 50 and SX 125: the supermotard bikes of 2006 onwards

APRILIA

2008 Aprilia SX 50 supermotard
2008 Aprilia SX 50. Photo by Maximilian Jilch, CC BY-SA 4.0 via Wikimedia Commons.

The Aprilia SX is a street motorcycle of the supermotard category sold by Aprilia since 2006. These bikes look like the enduro versions but have wheels, tyres and brakes suited to asphalt; today it is sold only as a 125 cc four-stroke.

Aprilia SX at a glance

Aprilia SX key facts
Sold since 2006
SX 50 introduced in 2006 to replace the MX 50; Derbi D50B0 two-stroke, liquid-cooled with a fan, about 15 kg
SX 50 carburettor and start 17.5 mm carburettor; kick start
SX 50 tyres 100/80 R17 front, 130/70 R17 rear on spoked wheels
SX 50 brakes 300 mm front disc with a floating two-piston caliper; 180 mm rear disc
SX 125, first series 2007–2013, a two-stroke Rotax 122, close to the SXV 450
SX 125, second series reintroduced in 2018 with a four-stroke engine to meet European emissions rules

The Italian page covers the SX 50 in detail and English Wikipedia the SX 125.

History of the Aprilia SX

SX 50

Aprilia SX 50 parked at Kirchstetten station in Austria
Aprilia SX 50 at Kirchstetten, Austria. Photo by GT1976, CC BY-SA 4.0 via Wikimedia Commons.

The SX 50 is the smallest of the SX series. By displacement it is a moped, though in looks it follows the more powerful versions (SX 125 and SXV 450 and 550), with the same mudguard, mask and other parts. It was introduced in 2006 to replace the Aprilia MX 50, from which it differs in both engine and chassis. The engine is the Derbi D50B0 block, a liquid-cooled two-stroke with reed-valve intake and a fan; English Wikipedia notes that it is the engine used in the Derbi Senda DRD, X-Race and X-Treme supermotos and in the Derbi GPR 50 and Aprilia RS 50 road bikes.

The airbox sits under the seat and is connected to a 17.5 mm carburettor. The exhaust is stainless steel and some versions have a catalytic converter on the manifold. The SX 50 has an unusually large 300 mm front disc, with a floating two-piston caliper, and a 180 mm rear disc with an opposed two-piston caliper. The 2006 bike had dual headlights and a red lion profile on black graphics, with a fully black seat; from 2008 the seat and mudguard turned red. With the 2010 model (2009 in some markets) a new front mask without the twin headlights and a new mudguard were introduced, and the graphics were simplified.

SX 125

The SX 125 was sold from 2007 to 2013. It was very similar to the SXV 450 and used the iconic Rotax 122 two-stroke engine. It was reintroduced in 2018 with a four-stroke engine instead of a two-stroke to respect European emissions standards.

Design and features

  • SX 50 engine: a Derbi D50B0 two-stroke with reed-valve intake, liquid cooling and a fan.
  • Brakes: a 300 mm front disc, bigger than the class average.
  • Wheels: 17 inch spoked wheels with 100/80 and 130/70 tyres, painted gloss black from 2009–2010.
Aprilia SX 50 parked at St. Valentin station in Austria
Aprilia SX 50 at St. Valentin, Austria. Photo by GT1976, CC BY-SA 4.0 via Wikimedia Commons.

Aprilia SX versions

  • SX 50 (2006–): the moped supermotard.
  • SX 125 (2007–2013): the two-stroke bike.
  • SX 125 (2018–): the four-stroke bike.

More Aprilia motorcycles are in our Aprilia collection, for example the RX, the RXV and SXV and the MX.

Aprilia SX questions and answers

What is the Aprilia SX?

A line of supermotard street motorcycles sold since 2006, in 50 and 125 cc.

Which engine does the SX 50 have?

A Derbi D50B0 two-stroke, liquid-cooled single.

When was the SX 125 built?

From 2007 to 2013 as a two-stroke, and again from 2018 as a four-stroke.

What did the SX 50 replace?

The Aprilia MX 50.

Sources

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