1952 AJS 7R Specifications

Name: 1952 AJS 7R
Brand: AJS

Classic • Specs last verified 31 October 2026

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1952 AJS 7R Overview

For 1952, AJS offers the 7R as a classic motorcycle with 349.2 cc on tap. The 1952 AJS 7R is built around a Single cylinder, 4-stroke, OHC Triple-Camshaft engine, a compression ratio of 12.2:1. Out on the road, the 7R delivers 29.8 kW @ 8000 rpm of peak power. Flat out, it's quoted at 193 km/h. In everyday use, the 1952 7R tips the scales at 129 kg and carries a 22.7 L fuel tank. Every technical detail, from suspension travel to tyre sizes, is covered in the full 1952 AJS 7R spec sheet below.

1952 AJS 7R compared with other bikes in the Classic category

Measured against other bikes in the Classic category in our database (up to 592 models, one entry per model), the 1952 AJS 7R comes out as follows.

With 193 km/h, the 7R has the joint 69th highest top speed of 438 bikes in the Classic category, 29% above the category average of 149 km/h.
Power output of 29.8 kW is higher than that of 394 of the other 591 bikes in the Classic category.
Narrowing the field to the 29 models within five model years of it, the top speed of 193 km/h is higher than that of 27 of the other 28.

1952 7R - Pros & Cons

Strengths

Capable power output: 29.8 kW @ 8000 rpm of peak output puts the 7R in good company among its rivals.
Large fuel range: With a 22.7 L tank, this isn't a bike you'll be stopping for fuel every hour - a real asset on longer trips.

Considerations

Carburetor fuelling: Carburetion is more hands-on than fuel injection - plan on periodic jetting and cleaning as part of routine ownership.
Drum rear brake: A drum rear brake is simple and durable, but expect less bite and more fade under hard, repeated use than a disc setup.
Chain final drive upkeep: A chain drivetrain is the most common setup in its class, but it's also the one that demands the most regular hands-on maintenance.

Wear Points & Servicing Notes

Heat management in traffic

Air cooling on the 7R keeps the mechanical layout simple, but heat management in slow traffic needs more attention than on a liquid-cooled bike - plan routes and gear accordingly in warmer conditions.

Carburetor maintenance

Being carbureted, the 7R is more sensitive to stale fuel and altitude changes than a fuel-injected bike - a carb clean and rejet restores crisp throttle response after any extended lay-up.

Suspension condition on used examples

Suspension duties are handled by Telescopic fork up front and Dual shocks at the rear. Weeping fork seals aren't a dealbreaker on a used bike, but they're a fair basis for negotiating price.

Final drive maintenance

Chain final drive on the 7R means routine lubing and tension checks are part of ownership - skip them and sprocket wear accelerates noticeably.

Frame & chassis check

The Tubular double cradle chassis holds up well with normal use; on a used bike it's still worth checking the head-stock and swingarm pivot area for impact damage or corrosion.

Low-speed handling

The 7R's 129 kg kerb weight makes low-speed control noticeably less effort than on a heavier machine.

7R - Buying & Maintenance Guide

What to check before buying

A pre-purchase check on the 1952 AJS 7R with its 349.2 cc classic should cover the same ground every time: service history, drivetrain condition, and any oil seepage around the casings. This model runs chain final drive, so check chain slack and sprocket tooth profile specifically - a worn sprocket is a cheaper fix now than after it's chewed up the next chain. Now 74 years old, this classic is as likely to show age-related wear (perished rubber, seized fasteners, degraded seals) as mileage-related wear. Start it from cold if you can - a well-kept 7R settles to a smooth idle within seconds.

Oil and filter changes

Oil changes are the cheapest insurance you can buy for the 7R's 349.2 cc single cylinder, 4-stroke, ohc triple-camshaft - keep to the manufacturer's interval rather than stretching it. With a 12.2:1 compression ratio, running the octane grade specified in the manual matters more than on a lower-compression engine. Use the viscosity grade the manual specifies, not whatever's on sale.

Carburetor upkeep

A 7R that's sat unused is almost always a carb-cleaning job before it runs right again - float bowls and pilot jets first, since they clog before anything else.

1952 AJS 7R - Frequently Asked Questions

What engine does the 1952 AJS 7R have?

The 1952 AJS 7R uses a Single cylinder, 4-stroke, OHC Triple-Camshaft engine with 349.2 cc of displacement. It is air/oil cooled.

What is the top speed of the 1952 AJS 7R?

The 1952 AJS 7R has a factory-quoted top speed of 193 km/h. Real-world speeds vary depending on rider weight, conditions and state of tune.

How much does the 1952 AJS 7R weigh?

The 1952 AJS 7R weighs 129 kg. This is the manufacturer's dry figure.

How much power does the 1952 AJS 7R make?

The 1952 AJS 7R produces 29.8 kW @ 8000 rpm of power.

What is the fuel tank capacity of the 1952 AJS 7R?

The 1952 AJS 7R has a 22.7 L fuel tank. At around 5-6 litres per 100 km, that is roughly 378-453 km between stops.

What brakes does the 1952 AJS 7R have?

The 1952 AJS 7R uses drum at the front and drum at the rear.

What gearbox does the 1952 AJS 7R have?

The 1952 AJS 7R is fitted with a 4-Speed transmission.

Key Specifications

Engine

Single cylinder, 4-stroke, OHC Triple-Camshaft

Power

29.8 kW / 40 hp @ 8000 rpm

Torque

Not recorded

Top Speed

193 km/h / 120 mph

Weight

129 kg / 285 lbs

Fuel Capacity

22.7 L / 6.0 US gal

Full 1952 AJS 7R Specifications

Year 1952

Model AJS 7R

Dry Weight 129 kg / 285 lbs

Fuel Capacity 22.7 L / 6.0 US gal

Oil Capacity 4.0 L / 8.4 US pints

Top Speed 193 km/h / 120 mph

Max Power 29.8 kW / 40 hp @ 8000 rpm

Displacement 349.2 cc / 21.3 cub in

Engine Detail Single cylinder, 4-stroke, OHC Triple-Camshaft

Bore x Stroke 75.5 x 78 mm

Compression Ratio 12.2:1

Cooling System Air/oil cooled

Exhaust 1-into-1

Fuel Induction Carburetor, 1 3/16 Amal

Ignition Lucas magneto

Spark Plug B6ES

Starter Kick

Clutch Dry, multiplate Ferodo

Final Drive Chain

Final Drive Ratio 4.87:1

Transmission / Drive 4-Speed

Frame Type Tubular double cradle

Suspension - Front Telescopic fork

Suspension - Rear Dual shocks

Brakes - Front Drum

Brakes - Rear Drum

Rims - Front 2.75 x 19

Rims - Rear 3.50 x 19

Wheels Steel, wire spokes

Specifications are compiled from manufacturer documentation and cross-referenced technical sources, and corrected on an ongoing basis. Spot an error? Let us know.

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