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Classic Lightweights UK
Classic Components 
 

TA chainrings

Peter Underwood
TA Chainring 5
In the post-war years most UK racing (and many touring) cyclists rode fixed-wheel machines with steel cranks.  At this time there was a strong resistance to alloy components as they were considered to be unreliable.  This especially applied to stressed components such as cranks and it was true that several of the British made alloy cranks such as the Lytaloy were known to break, split or strip threads.

The great majority of competitive cyclists were riding time trials and they were very reluctant to switch to gears although the riders in mass start races were more influenced by Continental fashions and were using 5 and 10-speed derailleurs.  Eventually, even the time triallists began to see the advantage of gears.

TA Chainring 15
Many riders still preferred steel cottered cranks and would either use imported chainsets such as Simplex or Stronglight 3-arm chainsets or Stronglight 5-pin steel cottered cranks fitted with TA alloy rings. As confidence in alloy cotterless cranks began to grow, the fashion for Stronglight cranks with TA rings carried on. For more information on Stronglight cranks see Hilary Stone's Classic Designs Section under Stronglight.   TA introduced the TA alloy cranks to go with their rings in the late 1950's


Left:- Image showing 5-pin Criterium (or Massed Start) 48T outer ring with 44T inner ring, mounted on alloy cotterless Stronglight cranks. The inner ring is bolted through each of the six arms with a spacer.   This gives the lightest option but has a drawback in that the pedal has to be removed to change the chainring size.  Serious racers never fitted the cap to cover the axle bolt.  Only one position on the 5-pin fixing will give the correct position relative to the crank.   See more details below to avoid red face!



When restoring a 50's machine you may find the selection of rings offered by TA rather confusing to say the least.  Below is shown a simplified version of the range of 5-pin rings on offer:

T A Chainrings 1 

The first Time Trialing offering is simple and straightforward, being a single ring which bolts direct to the cranks with a selection of sizes in 1/8 or 3/32 to give you whatever gear you may need.  There was also an adaptor to convert 5-pin to 6-pin

TA Chainring 14Right: Alloy Criterium adaptor from 3-pin steel cottered Stronglight crank
to 6-hole fixing for outer rings

The Massed Start (or Criterium) option uses adaptors to convert either from a 3-arm or the 5-pin crank to a 6-pin attachment for the outer rings. There are a range of sizes in 3/32 available although the diameter of the six fixing points for the inner ring BCD means that early TA advertise rings as small as 44 teeth but later this was reduced to 43. This adaptor is sometimes known as the Professional (or Professionnel - sic). Its main advantage is that the rings can be changed for racing without having to remove the pedals.   There is also a 5-pin Criterium similar in appearance to the Club Riding version but with a 44T limit to the inner ring!

The Club Riding (also known as Randonneur) option has an outer ring similar to the TT ring but with drillings for an inner ring on each of the six arms using longer bolts and spacers. Again the diameter of the six bolts (BCD) limits the smaller rings to a minimum of 36 teeth.

With this in mind TA offer the Touring option (sometimes called Cyclotourist), similar to the Club but with a much smaller diameter for the six fixing points.  This allows for an inner ring as low as 26T which should get you up the steepest mountains!

TA also produced a Cyclo Cross single ring with a dural chainguard rivetted either side of the chainwheel to prevent the chain from derailling when riding over bumpy ground.

The Track Racing option is 5-pin fixing with either 1/8 x 1/2" or 1" x 3/16. 

As you can see from from the above, it is essential to have the correct rings to create a matching pair.  I guess those with engineering capacity could drill their own outer ring although the drillings are counter-bored for the bolt heads.

TA Chainring 13 - wrong Left: Image showing wrong assembly of ring to cranks
Hint for those with an eye for detail:  There is only one correct position for mounting the 5-pin ring which will position two of the arms equidistant either side of the crank.  This is hard to describe but check before you put all the bolts in and tighten them.  It is galling to realise your mistake after the chainset is assembled and fastened to the axle in the frame. If you persist and hope no-one will notice your mistake, expect an email from the style police! 
This is doubly important if you have a TA Chain Trap.  These are extended (outward) bolts which utilise the fixing holes either side of the crank.  The extensions stop a derailled chain from dropping off the outside of the ring and getting jammed behind the crank (detail image available below on on TA Single ROAD Chainwheel page)

I am not familiar with TA triple chainsets but a third inner ring (needing longer bolts and spacers) is available for Criterium, Touring and Randonneur sets. To muddy the waters further TA also produced a selection of adaptors to convert available steel three-arm cranks to 6-pin mounting. The image below gives details of both the third inner rings and 3 - 6-pin adaptors:

TA Chainring 3

Although the Stronglight/TA combination was very popular in the UK, TA did produce their own chainset such as this cottered version available in 1960
TA Chainring 2

Having tried to give a brief overview of the world of TA chainrings I realise that it is impossible to cover all of the variations available and have listed seven detailed pages of the various models as of 1963 to enable you to fill in the gaps. Click on each type to view the page:

TA Type PROFESSIONNEL Chainwheels

TA Type CRITERIUM Chainwheels

TA Type RANDONNEUR Chainwheels

TA Type CYCLOTOURISTE Chainwheels

TA Single TRACK Chainwheels

TA Single TRACK Chainwheels (on ADAPTOR)

TA Single ROAD Chainwheels

Sources:
Everything Cycling - Ron Kitching 1963
Various editions of Sporting Cyclist
Various editions of Aids to Happy Cycling - W F (Sandy) Holdsworth