Introduction

Sporty Scooter by Aprilia

The model "Aprilia - SR 50 (AC, 1999-2001, ZD4LY)" is a sporty scooter produced by the Italian manufacturer Aprilia between 1999 and 2001. It belongs to the SR 50 series, which has been known for its dynamic appearance and innovative technology since its introduction in 1992.
The SR 50 was developed to appeal primarily to younger riders looking for a nimble and powerful vehicle for urban use, especially within the 50cc class, which can be ridden in many countries with a moped or AM license.

Development and Design

The SR 50 series was first introduced in 1992 and is considered a milestone in the sporty scooter segment. The ZD4LY, built from 1999 to 2001, belongs to the second generation of this model family, which was revised from 1997.
This phase brought a more aggressive design and technical improvements compared to the first series. Aprilia set standards with the SR series by introducing technologies such as liquid cooling (from 1994) and dual disc brakes (from 1997).
The ZD4LY, on the other hand, is an air-cooled variant (AC stands for "Air Cooled"), designed for simplicity and reliability while maintaining the sporty character of the series. During this time, Aprilia positioned itself in competition with brands like Yamaha and Piaggio, solidifying its reputation as an innovator in the scooter market.

Technical Details

Engine and Performance

Technically, the Aprilia SR 50 (AC, 1999-2001, ZD4LY) is powered by a single-cylinder two-stroke engine with a displacement of 49cc. The engine is air-cooled and fueled by a carburetor, enabling a power output of about 3.5 kW (4.8 hp) at 6,500 rpm.
The top speed is limited to about 45 km/h, with derestricted versions capable of reaching higher speeds depending on the country and regulations. The vehicle is equipped with a continuously variable transmission (CVT) for easy operation.

Chassis and Brakes

The chassis consists of a hydraulic telescopic fork at the front and a single shock absorber at the rear, providing the scooter with solid road handling.
The braking system includes a 190 mm diameter disc brake at the front and a 110 mm drum brake at the rear, which offered good braking performance for this class at the time.
With a dry weight of about 90 kg and a wheelbase of 1,275 mm, the SR 50 offers high maneuverability. The tires, sized 130/60-13 at both front and rear, emphasize the sporty claim and ensure sufficient grip.

Color Variants and Special Models

The Aprilia SR 50 (AC, 1999-2001, ZD4LY) was available in various color variants, which could differ depending on the market. Common paint options included "Rosso" (Red), "Nero" (Black), and "Grigio" (Gray), which emphasized the dynamic look of the scooter.
There are no clear indications that official special models were produced for this specific model. However, the SR series was known for offering limited editions or special designs in certain years, with such variants more common in liquid-cooled models like the SR 50 DiTech (from 1999).
For the ZD4LY, the focus was on standardized production for a broad customer base, with individual customizations possible through dealers.