We ride Aprilia’s wailing 125cc diva

By Time of article published Jul 22, 2014

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By: Dave Abrahams

Cape Town - Before the advent of the Nanny State, 16-year-olds in most European countries were permitted to ride a 125cc motorcycle on a category A1 licence. Any 125cc motorcycle.

Then, as now, the majority of 125s were basic budget-class machines, built down to a price rather than up to a standard but, for the privileged few, there were a number of bikemakers (nearly all Italian) who produced 125cc two-strokes that were, to all intents and purposes, Grand Prix bikes with lights.

And the queen bee of the class was the Aprilia RS125; after all, it’s difficult to argue with 24.5kW and ten 125cc GP world titles. Yes, it was horrendously expensive, but it looked the business, it was built like a Swiss watch and, properly looked after, it went like no other street-legal 125 on the planet.

But that was then.

Today, two-strokes are no longer eligible for Grands Prix, the infamous EU Third Directive limits 16-year-olds to motorcycles of no more than 11kW and the fabled RS125 has given way to the RS4 125.

Aprilia’s first four-stroke 125cc sports bike certainly looks the part; it’s styled after the first Aprilia to win a world title in a four-stroke category - Max Biaggi’s RSV4 World Superbike. It’s big enough to accommodate an adult rider and it’s built to eye-popping standards but with just 11kW on tap, it’s a bit of a sheep in wolf’s clothing.

Or is it? With peak torque (a whole 10.9Nm) at 8250rpm and a power band just 700rpm wide, it’s a wailing diva of a bike that demands absolute finesse from its rider before it will give you anything more than growling, reluctant propulsion.

If there is any motorcycle that will teach a teenager how to ride, it’s this one.

About 3000rpm and an educated clutch hand will get you off the line with surprising alacrity but before you have time to say “Wow!” you hit the (very violent) rev limiter.

You have to use the clutch for a decent first/second shift; after that you can get away without it and for the top three gears you don’t even need to feather the throttle. The standard-issue electronic quick-shifter will do it for you so crisply you won’t even feel it - all you hear is a sudden drop in revs.

The quick-shifter only works properly in the top three gears, however, and only under hard acceleration; get it wrong and its operation is violently jerky.


Shortly after 5am on a wind-still, bitterly cold but unexpectedly bone-dry winter’s morning I took the RS4 to a needle’s width shy of the limiter in fifth, quick-shifted into top and watched as the speedo slowly flickered up to an indicated 111km/h, for a true 106, at almost exactly 10 000rpm.

And it’s quite happy to run in the top third of its rev range all day, returning an impressive 3.83 litres per 100km thanks to state-of-the-art Magneti Marelli digital fuel-injection, with the added benefit that it starts first time, every time - although it’s a bit coldblooded and stalls easily for the first kilometre or so.

What’s that word I was looking for? Ah yes: finesse.

The same applies to the handling; the steering is very quick, as you’d expect on a wheelbase of only 1350mm, and accurate to a fault - the bike goes exactly where you point it and is utterly unforgiving of lapses in concentration.

The suspension is sophisticated by the standards of the class - 41mm upside-downies and a rear monoshock - but offers no adjustment other than rear reload. It coped well with my 106kg but would probably be better (less dive under hard braking) with a lighter rider.

You’d expect hair-trigger response from the radial-mount four-piston front brake and fashionable petal disc, but both front and rear brakes deliver very little initial bite, although they work well with a good squeeze.

However, many novice crashes result from locking up the front wheel, so maybe it’s a safety thing.


The seat is pretty well a plastic plank (and the pillion pad is even harder) but the bike’s ergonomics are well thought out. The seating position is relaxed and the controls fall readily to hand - rather too much so in the case of the engine kill switch, which I almost always knocked into the “Off” position grabbing a handful of front brake when swinging my leg over.

From the snout of its razor-edged fairing to the its multiple LED tail light the RS4’s jewel-like build quality puts it at the top of its class by far; its fit and finish are beyond reproach. As an object lesson in what can be done when the bean-counters are not allowed to interfere with the quality control department, it’s an eye-opener, but at R55 995, it’s almost too expensive even for its niche market. Almost.


Engine:124.8cc liquid-cooled four-stroke single.

Bore x stroke:58 x 57mm.

Compression ratio:12.5:1.

Valvegear: DOHC with four overhead valves per cylinder.

Power:11.0 kW at 10 500rpm.

Torque:10.9Nm at 8250rpm.

Induction: Magneti Marelli digital electronic fuel-injection with 32mm throttle body.

I gnition: Digital electronic with CDI capacity discharge.

Starting: Electric.

Clutch: Cable-operated multiplate wet clutch.

Transmission: Six-speed constant-mesh gearbox with electronic quick-shifter final drive by chain.

Front Suspension:41mm inverted cartridge forks.

Rear Suspension: Monoshock adjustable for preload.

Front brakes:300mm petal disc with J Juan four-piston radial-mount calliper.

Rear brake:218mm petal disc with J Juan single-piston floating calliper.

Front tyre:100/80 - 17 tubeless.

Rear tyre:130/70 - 17 tubeless.


Seat height:820mm.

Kerb weight (measured):147kg.

Fuel tank:14.5 litres.

Top speed (measured):106km/h.

Fuel consumption (measured):3.83 litres per 100km.

Price: R55 995.

Bike from: Aprilia South, Cape Town.

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