Here is a little more history on my AF1 I found while going back over some old messages from the previous owner.
3rd July 2022: "When we got it, the bike had been stored for 10-ish years but I cleaned the carb etc and it ran very well. After putting new tyres on etc and a fresh MOT, on its first ride it spat a load of gearbox oil out. After pressurising the crankcase, I thought it was crank seals so changed those and it made no difference, so I ended up splitting the motor down and saw that the gasket between the crankcase and gearbox had gone, so changed that and checked everything else as I went. One of the best Rotax lumps I've ever played with to be honest"
The 'International Motorcycle Catalogue' was a model listing directory published annually. I had several from period and I am missing the 1990 one with the Futura generation in, if I find it I'll update. Here are all the listings for the AF1 series.
In the 70’s and early 80’s Aprilia was mainly known for its small capacity and competition off-road motocross bikes, then at the Milan Motor Show in 1981 Aprilia debuted the all new ST125 (Strada) road bike to excited crowds.
On sale in late 82, but categorised as a 83 model, the ST featured a single cylinder liquid cooled 2 stroke engine produced by Italian company Hiro Motori. Design wise it leant on Italian market bikes such as the HRD and Malanca and also Japanese bikes such as the Yamaha RD/ Kawasaki AR models of the era. The Hiro motor was pre-mix only for 2 stroke oil, maybe this was due to its motocross based engine.For 1984 the ST remained in production alongside the new updated STX 125 model which featured a nose fairing and auto-lube, with the ST gaining the auto lube and is recognisable by its Aprilia-branded crankcases. As with the STX, the ST had a new exhaust system with a separate silencer end-can was used in 1984, replacing the long black pipe.
The last evolution of the ST came in 1985 with the AS125R, this model featured a significant upgrade in the form of a Rotax 127 engine with the RAVE powervalve, and a large jump in performance. The ST 125 was identified by the type code ST 125 and had DGM 50803.
Chassis specification:32 mm Marzocchi fork APS (Aprilia Progressive System) with Sebac rear shock Grimeca hydraulic twin piston front brake with 240 mm disc and a 160 mm drum at the rear. 18” wheels
Engine specification:The engine was produced by the Italian company Hiro Motori s.a.s. Reed valve intake system called H.I.S. (Hiro Induction System). Forced circulation liquid cooling Dell’Orto PHBH 28 AS carburetor. Six-speed transmission. Maximum power: 18.07 hp at 8250 rpm Top speed of 126.8 km/h (78.78mph) 400-meter acceleration tests from 50 km/h (31mph), 23.7 seconds/ 98.800 km/h (61.39mph)
Brochure translation:
The 125 ST APRILIA is a motorcycle that goes beyond conventional, focussing on himself the skills of a Gran Turismo and a Sports Car. Elegance of lines, absence of vibrations, comfort, fluidity of driving and low consumption blend perfectly with speed, recovery, road holding, braking and safety.
The liquid-cooled engine with internal circulation pump, allows homogeneity of temperature, consistency of performance and maximum noise containment. The front fork with advanced stud and the Mono-shock absorber rear with A.P.S. system (April Progressive System) they guarantee driving comfort and safety in curves with any background. The upgraded electrical system, equipped with a 130W generator with all battery services, offers greater lighting power, as well as supply consistency even at low rotation speeds, ensuring more safety in night driving.
The saddle is foldable with a safety lock to access the object compartment. The instrumentation ideally positioned and also equipped with a "fuel reserve light" is truly functional and complete. In this way it allows constant control of every part of the bike without creating problems or distractions driving.
Sometimes the rules on motorcycle homologation are a little bit silly, an example of this in the 80's was that to sell a bike into the Swiss market it could only have one headlight...
Aprilia were no exception to this so had to produce a revised fairing with a single square headlight to be able to sell a bike into the Swiss market. Honda also produced a single headlight version of the JC20 NSR125 which looks equally odd. Other examples worth checking out are the Swiss RC30, OW01 and even the 916!
After finally getting my bike fully assembled and in one piece, it was time to pack up and take it to the 2025 Classic Motorcycle Mechanics Show in Stafford.
I entered the bike as a private entry, and it was allocated a space in the Retro Hall, just off the main exhibition area. Unfortunately, the layout wasn’t clearly marked, so exhibitors were left to choose their own spots. The space I ended up with didn’t really do the bike justice — the lighting was poor, and the location felt a bit tucked away. To make matters worse, there were several empty spaces in the main hall’s private entry section where the bike would have been far better showcased, both in terms of visibility and presentation.
Despite these challenges, the weekend turned out to be a great success. The bike stood out and managed to pick up a ‘Highly Commended’ award, which I was absolutely thrilled about — especially considering it had only been completed a week before the show!
Throughout the weekend, I had the chance to chat with a number of visitors who had owned an AF1 back in the ’80s and ’90s. It was fantastic hearing their stories and memories of this iconic Italian pocket rocket — the nostalgia and enthusiasm they shared really added to the experience.
