Wheel Type 5 – Fixed Rear, 1926-55 Half Width, Rigid, not 1929-32 Colts

This type of wheel is referred to as ‘fixed’ to differentiate it from the quickly detachable (QD) type as the complete wheel including the brake mechanism and sprocket must be removed in order to repair a puncture unlike the QD version that leaves these parts attached to the frame.

Like the front wheel this was designed for the 1926 season by Val Page, the wheels were the only new parts other than the engine and gearbox for the re-vamped range and were a huge improvement over the earlier brakes. All versions use taper roller bearings that are adjustable and may require several attempts to get right. There should be just perceptible movement at the wheel rim as it is important that the bearings are not too tight because this will lead to premature failure. If your vehicle tester disputes this show him your copy of the owner’s guide. The rigid brake was always rod operated, never cable.

1926 The sprocket and brake drum are 1 piece, which in turn is bolted to the spindle tube, 1/2” diameter spindle, brake arm has a swivel piece attached, and brake reaction is looked after by a pin threaded into the frame, similar to the front.

1927 9/16” diameter spindle, brake arm is plain; the rod is attached using a clevis

1928-29 The hub and the brake drum with sprocket are pressed together. Spokes on the brake side start inside the brake drum; a guard is added in 1929 so that any broken spokes do not interfere with the brake. Grease retainers are altered and a cork washer used for just these years.

1930 Hub is wider, spindle longer and the main spindle nuts are now plain instead of having a shoulder that fits inside the frame slot so a sleeve to protect the thread from the effects of the wheel adjusting bolt is added to the right hand end of the spindle and because it has 2 flats on it, the brake plate must be orientated correctly relative to the spindle and the brake reaction lug or the torque arm will not line up. At the other end of the spindle 2 top hat bushes are used to do the same job. A dust excluding rim is added to the brake plate, initially the complete plate was painted but in later years the rim was chromed on some models. The brake reaction pin is replaced by a lug on the frame.

1931 A brake arm return spring is added, the wheel fitted to the duplex frame models, the Sloper and 4F, is almost the same.

1932-34 Fulcrum adjuster that became a bit of an Ariel trade mark is riveted to the brake plate The sprocket is made as a separate part, retained by 10 bolts, nuts and lockwashers to a drum that is now sheet steel, brake arm is moved from half past 2 to 1 o’clock, dust excluding rim is reduced is altered

1935 The sprocket/brake drum reverts to cast iron and the sprocket retaining bolt holes are threaded so the nuts can be dispensed with.

1936 Brake reaction is provided by a torque arm instead of a lug on the frame, the brake arm is moved to the 6 o’clock position and is forked with adjustment at this end instead of at the pedal end, shorter brake cam.

1938-41 The brake shoes are increased in width to 1 1/8”,

1942-49 The fulcrum adjuster is bolted to the brake plate instead of being riveted; many parts are given 1946 numbers.

1950-55 The slot on the right side of the frame for the spindle was enlarged to make room for a circular version of the thread protecting sleeve. There is another variation of this wheel fitted to the 1955 rigid HT about which little is known as so few exist, see a parts book. The sprocket bolt tab washers were deleted in 1954 but brought back again in 1955, the omission from the 1954 parts book was probably the fault of a bored clerk, bit like me really (I said bored, not boring).

For more information on wheel rims & spokes please click here