Christmas wishes 2025

Happy Christmas to all our Aprilia friends! We look forward to seeing your projects, restorations, ride outs and meet ups in 2026!

 

AF1 125 model variants and how the UK models fit in

Following on from previous posts on the UK specification Futura bikes I have done a little additional research. To date I can confirm the UK 1992 Sport Pro bike is 100% a GE model as I have had this confirmed by a frame number on an owners bike. I am still waiting on conformation of the UK 1991 Futura with the FM style seat unit and colour scheme, however we know that the frame, fork, swingarm, mudguard etc are all GE spec, so for now I am categorising it also as a GE (UK) bike until proven otherwise via a frame number.

Here is a simplified version for all the AF1 models and how the UK bikes fit in to that timeline.

And to separate out the officially imported bikes in to the UK, we had:

My bike - previous engine work

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"

1989 range from Performance Bikes magazine

 A look at the 1989 range from Performance Bikes Magazine

Magazine, International motorcycle catalogue 1988-1989

 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.

Magazine, Performance Bikes January 1988, Aprilia AF1 125

 This was one of the first UK road tests for the Aprilia AF1 Project 108 dating from January 1988.

ST 125 - the first Aprilia road bike

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.