This item listing is for a pair of the distinctive square headed rear wheel adjustment bolts, adjustment nuts and locknuts, to fit Gardengate Plunger Norton Models. The 'Gardengate' was the plunger type spring frame that Norton adopted for all sprung models from 1939, through to the early 1950's an was offered for OHV and SOHC roadgoing singles, pre-Featherbed (Dominator) twins and the racing model Manx Nortons from 1939-50.
This listing consists of two square headed bolts, 2 washers, 2 adjuster nuts and 2 smaller locknuts, all in stainless steel.
These bolts were designed specifically for the Gardgengate plunger design - the square of the bolt heads being of a diameter that will fit snugly into the rear wheel spindle slots, so the bolt will not revolve when adjusting the nuts. The square head is also of a special 'shallow' design to allow the greatest range of movement of the rear spindle - both of these features being lost if they are replaced with a 'normal' bolt, as many often were when they became worn or the thread damaged. Final point with these bolts was that on the original Norton design they had a rounded end, no doubt to help ensure the owner did not scratch himself, or end up locking the nuts - if hitting the end of the bolts with a hammer - as is a common thing to do when refitting the wheel. We have replicated these features on our bolts
Each adjuster has two nuts - but the innermost main adjustment nut is for a larger (Whitworth) spanner than the second nut, which is designed as a locknut - to be untightened then tightened before turning the main nut to adjust the chain tension. It should be noted that the main nut is specific to this application - being slightly deeper than commercially available 5/16^ nuts - no doubt because of the pressure being applied to pull the wheel assembly back, and was double chamfered (again, less common than other nuts of this period).
Although well designed - it is very common to find that original plunger models have their rear adjustment assemblies worn and battered - particularly these square headed bolts and nuts - where the threads eventually strip, and it is not uncommon to find them replaced with standard bolts, which do not work as well, and other commercially available nuts which are less deep and more susceptable to stripping their thread.
I am fortunate to have had a couple of 'New Old Stock' adjuster assemblies in my possession for many years unused (one of these being shown in the accompanying photographs), and these bolts and nuts are CNC manufactured in stainless to the same specification.
As an aside - for the square headed adjuster bolts, the dimension of the 'square' is no longer commercially available in stainless steel, so instead we have to start with much wider 0.750" diameter round bar, then machine that down to the final 5/16" shaft, and then mill the square's onto the head in a seperate operation - one of the reasons theses assemblies are not cheap, and rarely re-manufactured by others.
We also offer many of the other parts of the plunger assembly in the same section - as well as the fully assemble rear wheel adjuster assemblies (whcih included these bolts and nuts) - as Item 1042)
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