Workshop 01atters: The Millenniu01 Free Wheel Re01over

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As I signed off from writing the technical feature series, editor James suggested I added a small technical brief from our workshop each month to the YWAcolumn. So here goes:

All of us who run veteran/ early vintage motorcycles, autocycles, mopeds, velomoteurs and cycles with free wheel sprockets, will sooner or later need to remove the wretches. Free wheels fitted to multi gear systems are often drawn off a spline fit with a puller.

Commonly, the free wheel sprocket screws onto a fine clockwise thread applied to one (right) side of the rear wheel hub. In use, this progressively tightens, making removal ever more difficult. Thoughtfully, some cycle, autocycle etc makers supplied a peg type spanner to remove the free wheel sprocket.

Experience learned over the past 55-60 years of messing with such, is that while pain and blood is involved as the spanner slips, the device doesn't budge. Options include dismantling in situ to enable a better grip; fine, except little parts and small hairpin-like springs are involved, which invariably ping into the workshop's black hole, to never surface again.

An alternative to all of this is to use a new manufacture cycle free wheel removing tool, such as the Unior Universal Free Wheel Remover, which, with care, works fine on many autocycle/moped free wheels. But for the larger free wheels - which have enjoyed years of tightening abuse by riders standing on pedals to fire lusty 500cc direct drive veterans such as our 1911 499cc Premier to really tighten them onto the hub - a cycle tool is tested, although with care will work.

Fortunately, we have an alternative to hand, the heavyweight, cast Millennium

Free Wheel Remover, on semi-permanent loan from out friend Nick Harrison. It has been featured in a past YWAcolumn, but the accompanying series of photos demonstrate it in action, removing the free wheel from its past 30-plus years tightening process on a veteran rear wheel. Exactly the same procedure is employed for autocycles, mopeds and velomoteurs.

Engine Aluminium crankcases housed a single timing side

main bearing with a ball and roller on the drive side. These supported a built up crank assembly with a roller big-end, moving through a 100mm stroke. A 79mm piston in a cast iron barrel, resnlted in the classic Norton swept

volume of 490cc. Tue timing case enclosed a gear type oil pump and drive to separate camshafts, with the inlet driving a chain in an outboard housing to

the magdyno.

Lever cam followers gave way to tappets for 1948, allowing the timing case to be reduced in size. Tue flywheels became smaller

in diameter, but wider. Long pushrods in external tubes acted on the rockers for single exhaust and inlet overhead valves. Tue rocker

box was located on studs from the cast-iron cylinder head. A 11/,ein Amal 276 carburettor supplied

the mixture.

Later, the pushrods were made from aluminium, and a new one-piece rocker box was introduced, with a small cover for access to valve adjustment. In 1955,

the cylinder head also became aluminium and the carburettor changed to a 376 Monobloc. As fuel improved, the compression ratio steadily increased

to7:l.

Many parts are readily

available, just about everything can be found eventually, even castings. Pushrod Performance

offers a number of upgrades and specialist repairs that might be considered as part of a

restoration project.

[.iE Transmission

A steel primary chaincase provided an oil bath for the single row primary chain and the clutch assembly, which had five lined and six plain steel plates, with three springs. The clutch hub contained the rubber shock absorber assembly. Tue gearbox was Norton's upright pre-war type, but now with a neat end cover. In 1950, essentially the same 'box was revised to become the 'laydown' version. In 1956, the AMC gearbox became standard. Service items should be easily found. A well- maintained Norton transmission was the sturdiest of all in its era, but abuse or neglect can still cause problems. There are various sources for replacement parts. For regular riders, belt drive and an upgraded clutch might be worth considering.

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Electrics

The six-volt system was basic Lucas standard fare,

from the magdyno, the main harness to the head and tail-light assemblies. Tue headlamp shell was also the location for the light switch and ammeter. Earlier models had a pilot light beneath the shell. A critical part of any restoration is to get the

magdyno checked, a task that will usually call for specialist input. Neatly concealed electronic ignition conversions are becoming an increasingly

popular alternative to magneto overhaul. Other replacement Lucas parts are well catered for by

the aftermarket.

Cycle parts

The main frame featured

a bottom casting to make it a full cradle. The plunger version had first appeared on the prewar ohc singles. 1953, it was updated to pivoted fork rear suspension and a sub-frame supported a dual seat, instead of the former single saddle.

1957, the cradle casting was superseded with alltubular construction. The original bikes had single

sided wheel hubs with ball-journal bearings. The 1953 frame update brought a QD type rear wheel. The brake drums were 7in, with an Bin front listed for 1954on. 1956 full width hubs appeared. Rims were WM2, 19in diameter, originally fitted with 3.25 tyres. Fuel tanks of three different

types and capacities were fitted over the years.

Other tinware items, oil

tank, tool and battery box arrangements varied between frame type and sometimes model years. Replacement items will not be easy to find. Mudgnards were generouslyvalanced - the aftermarket should have something suitable

for anything missing or unrestorable.A prop stand became standard in 1950. A different dual seat design was adopted

in 1955. The following year brought many detail changes including different mudgnards and headlight. The style of silencer also changed over the years.

Suspension

Norton's oil-damped 'Roadholder' front forks had displaced girder types across the range by the time the ES2 reappeared postwar. Until 1953, rear suspension was undamped plungers. Later models had pivotedfork rear suspension,

controlled by twin shock Girling coilover dampers, although for 1956 only, Armstrong was

the supplier. Replacements for just about anything suspension-related should

be easily obtained.

With the wheel removed, the fix of the Millennium Free Wheel Remover to the sprocket is revealed. Moments later, the sprocket was free of its tool and a quick spin confirmed that despite the force needed to remove this reluctant component, no lasting damage was done, and, with it still complete, its tiny hairpin springs remain in situ, rather than lost forever in the workshop.

The second slider, with T-bar tightened stud, pointed at the business end, is located into the free wheel's slot intended for a peg spanner or similar, displayed pre locating visible to front right of photograph. Once located, tighten firmly.

And now for something completely different ••. My friend John White has a super collection of treadle-powered equipment, including this Millennium Spindle Grinder, which was cast, machined and built by the same firm who made the demonstrated Millennium Free Wheel Remover. Here, John has set up an example of the work it can undertake.

Mount parallel sides of the Millennium tool into a vice, firmly fixed to stout bench. Then by using the entire wheel as a lever, son Peter needed to give the wheel a strong anticlockwise twist ... And at the second attempt, the free wheel fastening to the hub gave up, to unscrew.

The Millennium Free Wheel Remover. The cast shaped end, to the left, and sliding V controlled by the Whitworth-threaded bolt, grip the free wheel's sprocket flrmly.