Quadrant Motorcycles

Today in Motorcycle History

1921 Quadrant 654cc 4½ h.p. Sidecar Outfit


Quadrant 2 1/2hp 654cc

One of the largest capacity single-cylinder outfits on the market - the 4½ h.p. Quadrant, fitted with a 654 c.c. engine.

Quadrant Modifications.

A Low-priced, Long-stroke, Big Single Sidecar Outfit.

BESIDES the excellent finish and sturdy construction o£ the big single Quadrant the most noticeable feature is the attractive price at which it is to sell. Completely equipped with Sturmey-Archer three-speed gear, chain and belt drive, a sound specification throughout, and a deep-bodied coach-built sidecar with good upholstery, the 4½ h.p. Quadrant is listed at £100, an extra £5 being charged for all chain drive. Without sidecar the two types sell at £80 and £85 respectively. Such prices for a thorouglily well turned out machine equipped with an engine of 85x110 mm. (554 c.c), cannot fail to draw the attention of the buying public.[1]

Sound Specification.

Regarding specification, the Quadrant remains largely unaltered, but a very neat circular section saddle tank replaces the earlier square type. Quadrant forks are, of course, retained, and it will be remembered that a rebound spring is incorporated in the design. The forks pass through the wide flat front guard, and the mudguarding throughout is sensible. Cast aluminium is employed in many places where sheet metal is more commonly used, and in addition the aluminium footboards, the silencer, and both front and rear chain guards are of the same material. A powerful Ferodo wedge type brake is fitted to the rear wheel, a rim brake being retained in front. We have had some road experience with the Quadrant outfit, and can testify to its roadworthiness and its pulling powers, for with its 5 to 1 top gear it is capable of taking a loaded sidecar up all normal main road hills.

The standard sidecar as fitted is roomy, and contains a large locker in the bulbous back and a smaller locker under the seat. Fixed to the body, so as to prevent rattle, the mudguard is of sensible proportions, and amply protects the passenger. Four points of attachment are provided for the stoutly constructed chassis and the body is fully sprung. 26x2½ in. tyres are fitted, and the equipment is excellent as regards essentials. A shock absorber is fitted in the rear hub of the chain-driven model, and a choice of Amac or Senspray carburetters is provided.

The Motor Cycle, November 17th, 1921.


Quadrant 2 1/2hp 654cc Aluminium Silencer

Made of aluminium, this novel double expansion chamber replaces the "canister" type of silencer on the Quadrant.


4½ h.p. MODEL. 85X110 mm. 654 c.c single-cyl. four-stroke; side valves; hand pump lubrication; Amac or Senspray carb.; gear-driven mag; Sturmey-Archer 3-speed gear; clutch and kick-starter; all-chain drive; 26x2½ in. tyres. Prices: Solo £85, with sidecar £105.

Quadrant Motors Ltd., Lawley Street, Birmingham.

As a thoroughly tried and amply powerful sidecar outfit, at a very reasonable price, the 4½ h.p. Quadrant occupies a secure position in its class. Allowing for its large capacity - large, that is, for a single - the engine possesses quite a remarkable top gear performance. At a casual glance, too, it impresses one as being cleanly and soundly designed. Technically, its only unconventional feature is in the position of the inlet valve behind the cylinder and the exhaust midway at the side; and this may account in no small measure for the engine's cool running and "slogging" capabilities. Instead of the old canister type of silencer hanging across just in front of the crank case, two neat aluminium expansion chambers are fitted, forming bulges in an open exhaust pipe which leads to the rear of the machine. Another noticeable detail improvement has been effected by rounding off the saddle tank. Quadrant spring forks, which are of conventional design, but embody a recoil spring, are retained, as is an ordinary horseshoe type front rim brake.

Aluminium chain cases are fitted to both chains, and on the chain-cum-beit model (which costs £5 less) to the primary drive. There is a transmission shock absorber in the rear hub of the chain-driven machine. The sidecars shown are commodious and strongly built, and have capacious lockers at the rear.

The Motor Cycle

Notes: 1. One article states "with an engine of 85x110 mm (654c.c.)", and the figure is repeated in the caption. B/S calculation gives 624.19cc. The bore/stroke given is incorrect, not the capacity. Bore/Stroke Calculator

Sources: Motor Sport Magazine

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