This item is for a full set of relacement springs to fit the Norton 'Gardengate' (1938-54) Plunger frame rear plunger units.
They are UK manufactured for us by a specialist spring manufacturer who has been involved in the making of springs for historic makes for many years and are excellent quality. A set of genuine original Norton plungers springs were used as the template - and ours match the gauge and poundage of these originals.
In the accompanying photographs is a picture of the type of frame these springs fit - this being known as the 'Gardengate' frame which was introduced in late 1938, and was used for various Norton models, through until (approximately) 1954. This type of frame should not be confused with the earlier (and much less common) 'Big Plunger' frame which was only produced for some SOHC/ES2 models in 1937/38 - if you have one of these types of frame, sorry - that frame uses very different springs to these. The frame in the photograph is a 1948/49 Manx frame - and was used to supply the original springs (as I knew they were original - probably not stripped for 50 years, but also would have had very little use), however, the same springs were fitted to all Norton models using this type of frame.
The set of 4 springs - consists of two thicker 'Compression' springs (these fit above the alloy sliders) and two slimmer 'Rebound' springs (that fit below the alloy sliders). Needless to say, you should be extremely careful when stripping old springs and fitting new ones - always wear eye protection and be aware that the springs can fly out, as can the covers.
I have removed many plunger units in the past - and often found that the original plunger springs are badly worn and tired (particularly on a well used road bike) - or sometimes even fitted with non original springs. If your springs are tired or worn then replacing them with a set of these springs should return your bikes rear suspension to the original Norton fresh specification
Final point - I may be having the rear plunger covers manufactured shortly - if possible using stainless steel for the polished covers. If you are interested in a set of these - email us at email@example.com, it may be useful to gauge the demand for these items