Riley Forecar 4 1/2hp (1904)

DU458 exhibited at Coventry Motor Museum
The 4½hp forecar was essentially the same as the 3hp model, but with the largest of the new engines built by Percy Riley's Riley Engine Co. This was also the first water-cooled Riley engine, all previous units being Air-Cooled. The biggest difference was that in order to accommodate the larger engine, its mounting position had to be moved from the front of the frame to a more central position under the cross member, where it was set vertically. The size of the single cylinder would equate to a 2 Litre capacity in a modern 4 cylinder engine.


Single Cylinder
RAC Rating 4½hp
Capacity 517cc
Bore86 Stroke 89
Carburation Longuemare Updraught


Freewheel in rear hub for pedal drive
Final Drive Ratio 8:1
Optional 2-spd:
1st g/r
5.4:1 2nd g/r 3.57:1


Springs at front, Sprung saddle


Front Band Brakes, Rear Block Brake.




Frame Size 23" (aprx. 580mm)
Wheelbase 4'5" (aprx. 1350mm)
Front Track 3'3" (aprx.980mm)
Wheels Dunlop tangentially spoked
Tyres 26x2 front / 28x2 rear.
Fuel Tank 2 galls


80 guineas
2-spd +5 guineas