Riley site

Red Roadster

Roadster differences

If you look at one of the original RM parts lists, you will many differences between the Saloon and Roadster.

Firstly, it was interesting to note the chassis numbers given for the various models. It appears that the three- seater begins at no. 2802 and the two-seater at no. 4731. My own three-seater for instance was first registered on December 10, 1949 and is no. 5377. However, there are changes shown on the three-seater as commencing a lot later than 4731. For instance, removable bonnet sides beginning at no. 4875 (with of course a corresponding change to the wing), modified left and right hand doors at 4731 (introduction of a packing piece with the door handle assembly) and revised wiring harness on both models from no. 5235 (to accommodate a separate solenoid). Does this, I wonder, mean that both two and three-seaters were made at the same time?

When you look at the details, you find of course that there are a lot of different parts which are just what you'd expect. There can't be a single body part which will interchange though I haven't had the stamina to check them all!

Some of the differences were a bit unexpected at least on a first look and some are still surprising even after thinking about them. What I'd like to do is run through some of these. For a start the chassis itself is different so you couldn't build a Roadster from a saloon. There are differences for instance in the exhaust tail pipe support bracket, the brake pedal stop, front extension, starting handle tube etc. Then the front shock absorbers are different. Wouldn't it be nice if someone had a Girling catalogue for the period and could get a Girling Part number and so perhaps a current equivalent? Rear shock absorbers by the way seem to be the same as on the saloon.

Hub caps, of course are different (all chrome). More interestingly the rear springs have nine leaves instead of eleven on the saloon. (I'll go an count mine tomorrow if I can scrape off all that muck!). On the three-seater, the steering gear is largely different from the two-seater and saloon which are identical. The difference as we all know is that the three- seater has the supplementary gear box to offset the steering column and give the extra passenger space. More surprisingly both Roadster models use a 17" steering wheel while the later 2 1/2 saloons have an 18" plastic wheel. I have an early type metal wheel which is also 17", but it come have come from a 12. Did early 2 1/2's have 17" metal wheels? Going with this on the three-seater if a different steering wheel centre to accommodate the dip switch.

This has disappeared on my car which has a saloon steering column and centre with a dip switch rather awkwardly mounted on the parcel shelf. As I've seen the same thing on other three-seaters, I guess it was a standard conversion done at the same time as the removal of the steering column gear change. By the way, has anyone an idea of other cars which used the same steering wheel centre to help in the search for another? And that of course brings me to the gear-change and box which are very different due to the steering column control on the three-seater. Two-seaters are the same as saloons in this area. The exhaust system is different though the book doesn't make clear how. The front and rear pipes are different so I'd assume the front box is the same. Interestingly enough there's no mention of a fish-tail on it as there was on the road tested car so that must have been an accessory.

The radiator, of course was different. As most people know, it is shorter and, I believe, has a differently shaped bottom tank. The throttle pedal, pedal assembly and all rods are different. The same applies to the handbrake assembly and rods and all clutch and brake rods. Though I've never measured it up, it looks as if the relative position of the driver in the wheelbase is different from the saloon. What that doesn't explain, however, is why the brake master cylinder, low and high pressure hoses and all pipes are different.

In the engine area, the oil gauge pipe is different and so is the adapter on the engine. Perhaps surprisingly the thermostat and elbow are different. Again, if we knew more, we might find that the thermostat opened further or sooner to compensate for the shorter radiator. Could this explain in part the well-known tendency for these cars to get hot and bothered in traffic?

Other odd points. On every Roadster I've looked at, there is a combined number plate and reversing lamp and the well-known and distinctive stop/tail lamps on the wings. The book, however, clearly refers to a number plate lamp and a reverse/stop/tail lamp - in fact, just like the saloon. I don't like to say so, but this one just looks as if the book got it wrong, unless of course anyone knows different. I said at the beginning that this isn't a complete catalogue of all the differences. The list for the three-seater runs to seventeen pages, the great bulk of which are body parts.

by Hamish Turner





as described in The Autocar, March 19, 1948.

PRICE, with open three-seater body, not quoted in Great Britain. Export only at present.
RATING : 16 h.p., four cylinders, overhead valves, 80. X 120 mm, 2443 c.c.
BRAKE HORSE-POWER: 100 at 4,500 r.p.m. COMPRESSION RATIO: 6.85 to I.
WEIGHT, without passengers : 27 cwt 2 qr. LB per C.C. : 1.26.
TYRE SIZE : 6.oo x 16in on bolt-on steel disc wheels.
LIGHTING SET : 12-volt. Automatic voltage control.
TANK CAPACITY: 20 gallons : approximate fuel consumption range, 20-24 m.p.g.
TURNING CIRCLE: (R) 36ft; (L) 37ft.
MAIN DIMENSIONS : Wheelbase, 9ft 11in. Track, 4ft 4 1/4in (front and rear). Overall length, 15ft 6in width, height 4 ft 7in.


From rest through gears to: sec.
30 m.p.h. .. .. 5.9
50 m.p.h. .. .. 14.0
60 m.p.h. .. .. 19.0 
70 m.p.h. .. .. 28.0 
80 m.p.h. .. .. 38.3  Steering wheel movement from lock to lock : 3 turns. 

(The later Two Seater versions were the same as the saloons, at 2.5 turns)
Speedometer correction by Electric Speedometer Car Speedometer Electric Speedometer 10 = 10
20 = 20
30 = 29.75
40 = 39
50 = 48
60 = 58
70 = 66.25
80 = 76
90 = 85.75

Speeds attainable on gears

1st 21-26
2nd 40-44
3rd 60-65
Top 98

WEATHER: Dry, warm; fresh wind. Acceleration figures are the means of several runs in opposite directions.


The Autocar went on to say...“This open model on the 21/2-litre Riley chassis represents a return to an open car in the modern style by a firm which through the years has usually offered open sports cars in addition to closed models. The current three-seater was designed with a view particularly to the American market and under present conditions it is unfortunately purely an export model. to the extent that no home market price is quoted for it. The price overseas varies, of course, on different markets but it is understood that it is closely comparable with that of the 21/2-litre saloon.No attempt has been made to provide a car with a very much higher maximum speed than that of the fleet saloon, and the same gear ratios are used.

Characteristically, the body is solidly built and there is thus no very great saving of weight over the saloon. With the latest engine, developing 100 brake horse power. the test results show that the acceleration performance is in some respects better than that of the saloon previously tested by The Autocar. An impression is certainly gained of the all-round performance being brisker than the saloon’s.It is intended purely as a two-three-seater of sporting character and additional seats are not provided in the tail of the body, which is devoted to a luggage locker of truly vast capacity. By the use for the first time on a Riley of a steering-column gear change the full benefit of a one-piece type of seat is gained as regards useful width available and ease of getting in and out by either door.

This open model feels every bit as “solid ‘ on the road as the closed car in spite of the absence of the stiffening effect of a steel roof, a fact which emphasizes the rigidity of the box-section frame which forms its foundation. The export nature of this model was stressed by the fact of the car undergoing test being fitted with left-hand drive.So well-known is the behaviour of the 21/2 litre Riley saloon, which has proved so successful in the post-war period, that it was no surprise to find that the natural cruising speed is in the region of 75 m.p.h., and this is a thoroughly comfortable rate on a top gear of 4.11 to 1.

The genuine maximum available closely approaches 100 m.p.h., with a fine surge of acceleration available on second and third gears. But it can be treated a good deal as a top gear car, for the engine proves decidedly more flexible at low speed than earlier examples, and picks up strongly the pinking that occurs under such conditions on the petrol at present available in Great Britain would probably be absent on fuels of higher octane value obtainable else-where.

This car’s averaging capabilities on a journey are al altogether exceptional. and it puts its 45 miles or so into an hour with consummate ease even over the usual English roads that constantly provide handicaps in the shape of bends and speed limits."


top How many were made? redlight

Designed for an American export market that never came good (only 50 went there), officially just 507 were made. This figure is now disputed by the authoritative RM Club, who believe 30 chassis numbers were missed and the total was only 477. The early ones (121 only) were made in Coventry, and from 1949 to 1951 the balance came from Abingdon.

Numbers produced were:

1949.  259

1950.  241

1951.  7

Let’s put this in perspective. There were 72,507 E-Type Jaguars made, and around 40,000 survive today. Like all Rileys, these Roadsters are rare. Possibly 146 complete cars remain worldwide today.

Alpine Riley

Variations from the saloons.

The car was not called a Roadster initially; this did not happen until late 1949. The correct name was a “Three Seater Tourer”

Some changes.

1. The chassis had additional outriggers to suit the Roadster body mountings.

2. The front suspension cradle is from a 1 1/2 to lower the bodywork.

3. Front shock absorbers were different

4. Rear springs had 9 leaves (instead of 11 in the saloons)

5. A shorter radiator was used.

6. Different bumper brackets support the heavy bumpers (set at 18" from the ground for the American market)

7. The petrol tank holds 20 gallons (up from 12.5)

8. The steering column was offset to the driver’s side to provide more room for three people.

9. The steering wheel was 17" (instead of 18")

10. An additional steering box changed the steering to 3 turns lock to lock, instead of 2 1/4. This extra steering box was dropped for the later two seaters.

11. The dashboard and firewall is further back. This necessitates special pedals and assemblies, longer cables for the choke etc, longer pipe to the oil gauge, different brake pipes and exhaust pipes.

Every single panel on the car was unique. Even the similar front guards and running boards are different to saloons. The grill is 2" shorter, cut down from the sedan versions. The dashboard is wider, and the fuel gauge is different. A petrol gauge switch allows different reading between the two tank senders. This was called a ‘reserve level switch’, but in fact there was no actual reserve fuel...

12. The boot lid and doors of the Roadsters were individually "fitted" to their particular body and marked with the last three digits of the body No. in wax crayon on the inside face before being removed for separate spraying.

Some experimenting was done by the factory to make a four seater version, and about six or so examples were built. They never went into production. The car looked something like a Riley Lynx, with two more seats extending into the large boot area.


The ‘2 seater’ model was launched, doing away with the horrible steering column gear change and reduction steering box. These cars have 2S in their chassis numbers, rather than the SS of the earlier cars.


RM Rileys imported to Australia


1 1/2 saloon

2 1/2 saloon





















































The Australian Riley Roadster Census.

 We continue to update the list of Roadsters in Australia. This was prompted by Peter Hocking’s (WA) revelation that 134 of these came to Australia, out of 507 (or 477) produced.

The starting point was a hand written list from 1977, covering various sightings around the East Coast. These were loaded into a database, and circulated to the various states. Fortunately, Western Australia (Peter Hocking) and QLD (Michael Branwell) were well organised; other states less so.

The Riley R.M. Club keeps a database. Worldwide they have records of 392 Roadsters of which 146 are recorded as being roadworthy. Here is their summary:

Total Roadsters
Australia 114 24
New Zealand
Spain 4 4
Portugal 4 0
Belgium 3 2
Italy 2 2
Others 9 6

 A couple of cars have been exported. But think about it. Around 70 or 80 Roadsters may be out there hidden in  chook sheds...

The list is purely a historical document, but will become increasingly useful for owners in the future. These cars are already 60 years old, and knowledge of their past adds value to them.


Colours Colours and trim.

Hubcaps on Roadsters were generally chromed instead of painted .

Wheels were sometimes painted to match the hood and upholstery, which matched unless to special order.

Black wings were available with all paint colours.

Between September 1948 and April 1949 standard colours were:

  • Ivory paint with red trim.

  • Black paint with red trim

  • Scarlet paint with beige trim

  • Light green paint with beige trim.

  • Ming blue paint with beige trim.

After April 1949 to January 1951, available colours were:

  • Black paint with beige, red or green trim.

  • Autumn red paint with beige trim.

  • Clipper blue paint with beige trim.

  • Red paint with beige or red trim.

  • Ivory paint with beige or red trim.

  • Almond green paint with beige trim.

  • Sun bronze paint with beige trim.

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