APRILIA SR50


Since its European debut in 1992, the SR50 has been one of the most popular 50cc scooters worldwide, with well over a million sold and a huge aftermarket community. The SR50 brought advanced technology, sporty style and huge power (for a 50cc) to the scooter scene. The SR50 was arguably the first ‘sports’ scooter due to its sport bike inspired styling. Other landmark firsts accomplished by the SR50 include the first 50cc scooter with 13” rims, first scooter with direct fuel injection and the first 50cc with disc brakes front and rear. Aprilia also claims the SR50 was the first liquid cooled ‘sports scooter’, but this is only true if you accept Aprilia’s earlier claim that the SR50 was the first ‘sports scooter’. Personally I’d give the nod to the 1983 Honda Beat for these two firsts, but in any case Aprilia has poured a great deal of effort and innovation in the SR50. In today’s cluttered market of lower end machines, the SR50 stands out as a high quality machine for enthusiasts.

2004 Aprilia SR50 DiTech Aprilia SR50 Factory - Orange

Generations
There has been two main generations of the SR50, with a few different versions sold during each. The first SR50 debuted overseas in 1992, and wouldn’t reach the USA & Canada until the 1999. The original SR50 (above left) was first offered with a simple air-cooled carburated motor, but Aprilia added liquid cooling for 1994 and direct fuel injection for 1999. From 1999 to 2003, the original generation of SR50 was sold in both versions. The carburated version was called the SR50, while the direct fuel injection model was called the SR50 DiTech. Aprilia also varied the graphics on this generation of SR50 and used names like SR50 Sport and SR50 Racing to denote the different variants.

Generation One Aprilia SR50
For the 2004 model year, Aprilia released an all new SR50 (above right) inspired by Aprilia’s flagship bike, the RSV1000. This generation remains on sale as of 2014. This second generation of SR50 is sold in both carburated (SR50 R) and direct fuel injection (SR50 R Factory) versions, but North American customers are only offered the higher end ‘Factory’ version. Besides the new styling with the lion’s head graphics, the second generation SR50 also boast a more rigid frame and a significantly improved DiTech system. Aprilia was able to double the maintenance intervals and reduce oil consumption by 60% with the refinements they made to the system. Power, milage and starting ease were all improved. For 2010, Aprilia switched to a Piaggio made core engine but it still uses the same DiTech system. For the 2013 model year, Aprilia created a no extra cost special edition called the Replica SBK dedicated to #3: Max Biaggi.

Engine
The SR50 has a huge following of enthusiasts partly because its been around so long and it looks awesome, but also because this is a fast scooter that can easily be made quite a bit faster. It’s not uncommon for highly modified SR50’s to exceed 80mph. In its stock form, an SR50 is capable of roughly 50mph if it’s not restricted by Aprilia. In many parts of North America this scooter is restricted to either 70km/hr (43mph) or 50km/hr (30mph) to meet applicable legislation. Riding a 30mph restricted SR50 fresh off the dealers floor is disappointing, but a ride on a de-restricted SR50 really impresses with an abundance of power and satisfying top speed. The SR50 doesn’t even sound like it’s working hard at 50mph.

The SR50 is restricted in two ways. First, there is a restriction in the computer software that runs the highly advanced SR50. You can remove this yourself with a GameBoy (does anyone still have one of these?) or you can ask your dealer to switch it to ‘test’ or ‘development’ mode which removes the performance limitations. Secondly, there is also a restriction in the drivetrain that limits the top speed of the scooter by
Aprilia SR50 - Front View
preventing it from reaching taller gear ratios. You can learn more about changing this here. Even if you don’t want to exceed the restricted speed of your SR50, you should still remove at least the computer restriction because with this in place, the scooter doesn’t rev high enough to accelerate with any authority. Restricted SR50’s make just under 2hp.

Forgetting about the power restrictions which aren’t Aprilia’s fault, the SR50 has one awesome engine. Aprilia has sold the SR50 with three different motors (Minarelli, Aprilia/Morini and Piaggio) over its lifespan depending on the year and country you live in. North Americans were sold the Aprilia/Morini motor from the SR50’s debut here in 2001 until 2009, when the switch was made to the Piaggio engine. Piaggio (parent company of Vespa) bought Aprilia early in the new millennium (2004), so using a Piaggio powerplant likely lowers their costs. All SR50’s have liquid cooling and all the ones sold in North America have direct fuel injection (aka DiTech). Real world milage for the SR50 is really impressive at 80-90mpg. It’s almost as good as the fuel sipping 4-strokes 50’s out there while offering far more power. The only negative things to say about the SR50’s motor are the inherent downsides to a 2-stroke (emissions, shorter engine life) and the shorter lifespan of the high output motor. It’s fairly common to give an SR50 a top end rebuild every few years.

Brakes / Suspension / Handling
The disc brakes front and rear are an uncommon find on a 50cc and the SR50 offers perhaps the best braking of any 50cc sold here in North America. In a time when so many manufacturers cheap out on scooter brakes and utilize low cost drums, the SR50 stands out with excellent discs at both ends. The lever feel is great and overall performance is second to none.

Aprilia SR50 - Gauges
The handling of the SR50 is pretty good with its low profile tires and larger diameter wheels. The only thing that really holds this scooter back is the higher than average seating position. The high seat is comfortable for larger riders, but it means you’re sitting fairly high off the ground which gives a top heavy sensation. Most riders will adapt to this and find they can handle the SR50 well, but shorter riders may find this to be a problem.

Storage & Convenience
In addition to the engine, the rest of this scooter is top notch too. The SR50 also has moderate underseat storage (some larger helmets won’t fit) and a neat cubby hole in the front of the seat for more of your stuff (only on second generation SR50’s). The instrumentation of the SR50 is superb - actually it’s the best there is for any small scooter hands down. The analog tach combined with the
Aprilia SR50 Ditech Factory l
digital speedometer and fuel gauge is best in class. The digital instrumentation tells you everything you’ll ever want to know including fuel milage, top speed, trip length and much more.

The bottom line is the SR50 is a great looking, powerful and top notch quality scooter that is sold at a premium price. The MSRP hovers around $3g in the USA and $4g in Canada ,which puts it on par with a 50cc Vespa and about $1000 more than quite a few other nice scooters. The SR50 certainly warrants its higher than average price tag due but it includes attributes that not every scooterist is after, so consider carefully what suits your goals. The SR50 is really an enthusiasts machine. If you’re looking for slower practical transportation, something like Yamaha’s C3 has got the SR50 beat almost across the board (price, emissions, fuel economy, storage). The sporty styling, Aprilia quality and highly upgradeable nature of the SR50 seems to be what draws both buyers this scooter. If these attributes appeal to you, then you’re going to love the SR50.

OWNER REVIEWS (2) - Browse the Aprilia SR50 Owner Reviews          REVIEW - Add a Review of Your SR50


Pros:
- Unreal braking
- Class leading power
- Loads of go fast parts
- Huge community
- Sporty Styling
- Great milage for a 2-stroke

Cons:
-
High seat height
- Motor lifespan

Links:
SR50 Service Manual (2nd Generation) - Very helpful for the DIY’er mechanic.
Submit Review - Own this scooter? Add your thoughts to this site.
SR50 DiTech Forums - Huge group of SR50 DiTech enthusiasts
MotorscooterGuide Forums - Visit the forum to chat about all things scooters.
ApriliaParts.co.uk - Microfiche with exploded parts diagrams
SR50 Service Manual - Essential info from the Factory for working on your SR50
SR50 R Factory Aprilia Brochure - Nice PDF download from Aprilia

Key Specs:
* Engine: 49cc, single cylinder, liquid cooled, 2-stroke
* Compression: 12.5:1 (’92 - ’01), 11.5:1 (’04 - ’09), 12.1:1 (’10 - present)
* Bore x stroke: 41 x 37.4mm (Gen 1), 40.0 x 39.3 mm (2001 - present)
* Fuel system: Fuel Injected
* Ignition: CDI - capacitor discharge ignition
* Starter: Electric
* Frame: Steel
* Lubrication system: Oil injected
* Clutch: Automatic centrifugal dry clutch
* Weight: 199 lbs (Gen 1) , 198 lbs (Gen 2)
* Seat height: 32.0 (Gen 1), 32.3 (Gen 2)
* Overall height: 46.8” (Gen 1), 44.1” (Gen 2)
* Overall length: 73.5” (Gen 1), 73.2” (Gen 2)
* Overall width: 28.1” (Gen 1), 27.8” (Gen 2)
* Wheelbase: 49.3” (Gen 1), 50.8” (Gen 2)
* Front suspension: Hydraulic fork, 90 mm wheel travel
* Rear suspension: Engine unit acting as swingarm, 72/70 (Gen 1/Gen 2) mm travel
* Rims: 3.5” x 13”, Five spoke, light alloy, tubeless
* Tires: 130/60-13 (front and rear)
* Front brake: Single 190mm disc, twin opposed 30mm pistons
* Rear brakes: Single 190mm disc, twin opposed 30mm pistons
* Fuel capacity: Gen 1 = 8 liters (2.1 gallon), Gen 2 = 7 litres (1.85 gallons)
* Gen 2 Color options: Aprilia White, Silver Crowd, Code Orange, Diablo Black