Classic Lightweights UK


The Constrictor Tyre Company Ltd - Nursery Lane Works, London E7.


Submitted by Peter Underwood


The Constrictor "Conloy" derailleur was made between 1947 and 1952 or 3.

It is made from stamped aluminium plates and it is a 4-bar link design (Parallelogram)with a single pulley. It is designed as a 3 speed but by filing away some aluminium on the lower rectangular plate top, the travel is increased.  Other factors prevent it from travelling more. When changing gear, it wants to go onto the large sprocket, rather than the one just smaller on the downshift but the upshift will engage the next smaller one.

It seems to be very sensitive to spring tension. Actually, I am surprised how well it works for its crudity.  Keith Hellen

constrictor-components1 constrictor-components2
Left is original box for the hub shown on the right

Constrictor Hubs

Constrictor hubs were marketed both pre- and post-war, they sold both alloy and steel hubs which were manufactured for them, some by BSA in the UK whilst others were imported from the Continent.  These hubs were all stamped as 'Constrictor'.

In the 1955/56 Constrictor catalogue they advertised both Viper hubs and Conloy hubs, defining the Viper as 'suitable for derailleur gears'.  In the image below one can just make out the oil nipples on the end of the axles.


The catalogue goes on to say:

"Viper and Conloy hubs are precision made lightweight types, with standard size flange.  The Viper has a steel barrel with Conloy flanges; one side is screwed for standard cog and lock ring and the other for freewheel block.  The spindles are drilled up each end and are turned in form of oil nipple.   Oil can be injected straight into the bearings.  The Conloy hub is turned from solid bar.  The rear is screwed for double cog only.  The spindles are the same as fitted to the Viper."

It should be noted that the use of oil to lubricate hubs was probably confined to really keen racing enthusiasts as it was more common to use grease for hubs and bottom brackets.  The attraction of oil was the reduced friction it offered but the downside was that the bearings would need regular lubrication, probably every week for the keen owner.

Perhaps it should be said that 'Conloy' refers to the 'special' Conloy alloy used to make Constrictor components.

The catalogue also lists their 'New Quick Release Drop Out Conversion Set' 


It goes on to say: "A form of wheel drop out that holds the wheel securely and without fear of slip.  The existing hub cones, nuts and washers, etc. are retained but the spindle is replaced with a hollow one.  Carrier slides are fitted to the fork ends and a steel skewer is passed through the whole and locks the wheel in position.  A derailleur can be fitted and this remains undisturbed when the wheel is removed.   The wheel also goes back automatically into its correct position and does not need centralising.  Finished in polished chrome and cadmium."
The catalogue doesn't make clear if this conversion can be used with all makes of hub or whether it will  work only with their own hubs.

'Constrictor Circum Spoking' 

Circum 2The sheet says:  "CIRCUM is our new and patented device for wheel building.  Having two spokes in one length, you do away with the trouble of having the heads broken off and the wheel therefore getting out of truth.   Each double length of Spoke (right) has a 3/8" diameter circle in the middle and this is placed round bumped or protruding collars of which there are ten on either side of a Rear wheel.  This enables one to use a smaller Spoke and the tangent comes further along the Spoke and when tied and soldered as we do all our Circum 3wheels, you get the most rigid wheel possible.    For this season we have designed special Hubs both in Alloy and Steel, so that our flanges or discs can be riveted on and we shall fit and supply complete.  We were anticipating when we first patented and introduced this new method of Spoking that we should adapt it to an ordinary type of Hub, but we prefer to go along with a complete unit for this season.   With the Front Hub (left), the flange is not so wide, as from our experience of experiments, a rolling wheel does not want this rigidness and at the same time it gives us better alignments of spoking."

The double-spokes were sold in 15, 16 and 17 gauge.

The Constrictor Asp rims, both HP and Sprint, were the first choice for many of the top Clubmen of the era but many were built with Harden or Airlite hubs.  For some reason the Constrictor hubs were not so popular and for this reason there are not many of them in circulation today. Constrictor also produced their own wingnuts (right) which again are very rare.

I guess a collecter's dream could be to have a classic frame equipped wholly with Constrictor equipment including an Osgear plus D.C.W front changer, hubs, rims, wingnuts, lamp bracket, toe clips and straps, pedals, honking rubbers and the combined handlebar end plug and container (sold with rubber solution, patches and sand paper).  It would be too much though to hope to find usable Contrictor tyres or tubulars to complete the showpiece.

Constrictor wingnut

A collector-friend of mine recently went to pick up a frame which had been for sale, the seller asked if the collector had heard of Constrictor.
He was taken upstairs and shown a veritable treasure of things Constrictor including showcases, and draws with components in them.  We have been allowed to show some of this with the images below.

Showcase with derailleurs, wingnuts, lamp bracket, hubs, pedals, rim samples, adjustable stem and much more - see what you can identify!

More treasures for you to identify including pedal, clips, gears, brakes and cranks.

Several drawers such as this one were found.  At first glance there may not seem to be much
but a second look shows Circum hubs, the desirable Costrictor lamp bracket, cranksets,pedals and
hubs - this is just the top layer.  After sorting through, the following were collected

Constrictor toeclips Sir? Alloy toeclips are always rare - or perhaps some.......

.....rather tasty wingnuts? Don't look under the glass, you will only feel sick with envy.
Especially when I sort out some.......

Circum hubs and spokes!!!!! Only cleaned one up so far
(Circum hubs only shown in brochures 1938-40)

A wonderful collection of catalogues - and there is more-

Does this make up the complete set?

C T C award for the application of Conloy metal awarded 1927

Constrictor stand at the cycleshow, Olympia - can you identify the year - 1930s? Look at the complete bikes.

Another 1930s stand at Olympia.
Second from left is Lesle Bane, director. Third from left is another director, Joe Bane
First from right is David Cavall, works manager.

Constrictor stand 1937/38
David Cavall 3rd left, Leslie Bane 4th left, Joe Bane 5th left.

A post-war Earl's Court stand with more concentration on gears - 1950s

Meredith transfers which were used to 'badge up' bikes imported from France