This is the 'long tang' type gearbox kickstarter spring fitted to the 3 Speed Sturmey Archer CS type gearbox - as fitted to most Norton SV and OHV models in the mid 1920's to approximately 1932. We also sell a similar CS type spring with shorter tang (Item 1065), See listing detail for information on each type.
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 just as per the original spring. This spring came from a CS gearbox fitted to a 1930 Norton OHV model, and the original spring even had pitting along its length - indicating it is a very old spring, and possibly the original spring fitted to that gearbox (very kindly lent to me by a customer who owned the bike).
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.
If you own a Norton model (or indeed any other similar aged marque that may have also fitted Sturmey Archer gearbox's in this period), then it is important you also look at our similar Item 1064, as we offer two different type of springs from this era, that although are very similar, have slightly different tang length's, and the spring ends are at different positions - so please check the accompanyning photographs for both listings before ordering - we try to show the exact differences between the two different types, so you can select which looks most correct for your particular gearbox.
It is difficult to be definitive about which year and which models used which particular spring - as there seemed to be many different Sturmey Archer gearbox's with minor variations through the 1920's (and Norton Spare Parts List did not seem to clearly identify one type from another) - but this type has a slightly longer tang than Item 1064 - and the pattern spring we used definitely came from a 1930 model - which indicates that this spring was probably more likely to be fitted to late 1920's-early 1930's Norton's using the CS gearbox, but it could be this spring type was also fitted on earlier models - but in parallel to the short tang type gearbox (Item 1064).
However, it is worth looking at the picture of gearbox shown for Item 1064 as a comparison - as this is taken from a 1925 Norton model, and that gearbox looks to have been fitted with the 'short' length tang kickstarter spring. So, although not definitive - it may be possible that the earlier versions of the CS gearbox were fitted witht the short tang type (Item 1064), and later types of this gearbox were fitted with this spring (Item 1108). To support this - you will notice that the later (i.e. 1930) type gearbox shown here also had a pressed steel kickstart lever retaining clip bolted to the gearbox cover just above the kickstart shaft, which the mid-1920's version did not have - which may explain why the tang lengths are different, to avoid fouling this clip.
When looking at the phtograph that shows the 'clock' position the tangs are positioned at for both springs - it should be remembered that it would be normal to pull the kickstart back (i.e. anticlockwise) slightly, so the kickstart is under slight pressure, even when at the top of its stroke - so take this into account when looking at the spring end positions.
Both this spring (Item 1108) and the other CS spring (Item 1064) have a kickstart spring tang that protrudes outward from the gearbox approximately 20mm, meaning the kickstart lever is very close to the gearbox cover. The later CRS gearbox spring (Item 1065) protrudes out much further, meaning the kickstart shaft protrudes further out from the gearbox end cover than the CS model.
A final point - I am not an expert on early Sturmey Archer gearbox's (very few people are these days for obvious reasons!) - and have only pieced together the information shown here from looking at many photographs from different models, customers and friends who still have these - and looking at the few Sturmey Archer gearbox spares I own myself. If you think you can provide more information - or own models with other types fitted - feel free to email us on sales@racingvincent.co.uk - we will be happy to update these listings with more information, or add other springs if patterns become available.expert
The length the tang protrudes on this spring is approximately: 44mm (this being the straight section between bend and start of top loop)
The outer diameter of the spring is approximately: 47.5mm
The kickstarter tang protrudes out approximately: 20mm from the main coil spring
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! It is slightly more expensive than later springs, as we have had to pay setup on a smaller size of batch than the later springs - hope this makes sense.
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