Normal Reliant axle ratios and other info.
Reliant regal (side and OHV, 600, 700 and 750 sidevalve)
These axles have a posted ratio of 8x35 which equates to 4.375/1 The interesting thing with these is they have a 3 piece diff casing and a bolted on crownwheel and they are by far the easiest axle to convert to chain drive.
Reliant Robin 750cc and Kitten van..........Axle ratio = 3.545/1
Reliant Robin 850cc, Kitten and most Rialto's........... Axle ratio = 3.23/1
Reliant Rialto 2..............Axle ratio = 2.78/1 The Rialto 2 was a different animal to the others and only had a short production run in the early 1980's. Mostly on 'B' and 'C' registrations, these cars were fitted with higher compression engines that Reliant designated the 'Economy' engine and enthusiasts dubbed the 'yellowtop' due to the colour of the rocker box. Any genuine Rialto 2 engine can be identified by the letter 'E' stamped at the end of the engine number. The axle ratio differed from the other models and the diffs can sometimes be identified by the letter 'B' stamped on the diff casing.
All axles have a capacity of 1.28 litres of EP90 oil
Brake Slave cylinders are Bmc mini items on most axles (not sure about regal models) lucas/girling part 67660042
Prop shafts have the same flange fittings but there are 2 different diameters. The Regal range used one of 1-1/2" diameter (look neater on bike trikes) The later Kitten, Robin, Rialto ones are 2". These use Hardy spicer HS194 Universal joints.
The PCD is 4" (101.6mm) so any wheel with a 4stud x 4" or 102mm PCD should fit ok as long as the offset allows the tyre to clear the frame.