This is the gearbox kickstarter spring fitted to the 3 Speed Sturmey Archer models that were fitted to Walter Moore Norton CS1 and ES2 models in the late 1920's, through to the first Arthur Carroll engines and other models, to approximately 1932. It has a long tang that protruded out and wrapped around the kickstart.
Price is each.
We used a genuine original Sturmey Archer (for Norton models) kickstart spring for the pattern for manufacturing these springs - so they are as per originals.
This spring is unusual, in that it is has forward facing tang and loop, which fed through a hole in the kickstart spring cover (see accompanyning photos), and then looped behind the shaft of the kickstart lever. The length that this tang protruded is important, as other Sturmey Archer gearbox's had a similar spring - but with a shorter length protruding (see also Item 1064).
The length the tang protrudes on this spring is approximately: 44mm
The outer diameter of the spring is approximately: 47.5mm
It is difficult to be definitive about exactly which Sturmey Archer Gearbox's and models this spring was fitted to - but it is certainly of the type that was fitted to the sporting Norton Models from 1927 through to approximately 1932 - as it is listed in the 1927/28 Norton Spare Parts catalog for Walter Moore type CS1 and ES2 models. At this point the spring was shown as part number 4585. I cannot be entirely sure - but I believe the gearbox was known as the CRS type gearbox (please email me if you think I have got this wrong!).
It was then shown again in the 1930-31 Spare Parts Catalog, by which time this gearbox was now being fitted to the newly introduced Arthur Carroll type SOHC CS1 engine, as well as the ES2 models. By this time the part number had changed to 5X44. See accompanyning photos for exerts of both these catalog pictures.
The following year (i.e. 1932) the Sturmey Archer 4 speed gearbox was introduced for the SOHC Mod30/40 models with a different kickstarter spring type (see Item 1066) - but the 3 speed gearbox was still listed for the CS1 models - so although I cannot be sure if the spring design changed, the 1932 3 speed may have continued to use this spring type - and it may have also been used on other models at that point in time (again, please email if you have a 3 speed of 1932-34 design and can confirm this, thx).
This spring may have also been fitted to other manufacturers models fitted with Sturmey Archer 3 speed gearbox's from mid 1920's to early 1930's - if unsure, the important dimensions to check are shown above - the distance the tang protrudes to reach the kickstarter shaft, and the width of the spring (and again - I would be happy to update this listing if anyone knows of other models using it).
As a final point - as at time of the writing this listing (Jan 2022) - I am in the process of having a small batch of the spring covers manufactured - as shown in the centre of the photo with the springs and covers together. These were tin covers (although we may need to machine from solid), with a hole for the forward facing tang to protrude. Email us on sales@racingvincent.co.uk if you wish to reserve one.
This is now an extremely difficult spring to find, and many original gearbox's are likely to be suffering with the original spring worn and tired - this new spring should help revitalise the kickstart lever returning!
Your basket is empty.
