Before I put the wheels back on I really want to sort out the suspension. The rear will be relatively straight forward after the front is sorted.
For the front I have been investigating what can be done with the stock springs and cutting them. I managed to work out what the stock spring rate is with the dual windings, it is a really low 3.3N/mm, which according to some literature, is suitable for riders weighing less than 50kg! Haha. Now I don't know if I am exactly right with all this stuff but it makes pretty good sense to me - see that attached equation plus the weight/spring rate charts from various manufacturers. Many replacement springs for classic bikes are however much higher ratings - up towards 7-10N/mm for riders ranging from 75-105kg. I'll do some of my own experimenting. The second rate on the spring is a lot more in the ball park at 4.5N/mm.
I started out investigating cutting the spring in three locations, one to separate the dual rate, then another two cuts to shorten each spring based on a percentage increase in spring rate - see attached how I thought a spacer could be made to connect the two and keep their compression separate, plus a chart of some calculations I made. This way, the dual rate could be retained.
Once I did the calculations and did a test cut of the spring, I realised this is not a good idea. The tightly wound part of the spring becomes coil bound quite quickly (did a test compression) and becomes useless (this is the purpose/intended behavior), plus cutting in a few places is a pain. I figured after reading a lot, especially racetechs literature, that straight rate springs with correct rate, preload and damping are much easier to control, adjust and ultimately will behave as intended = predictability and hopefully a well performing fork.
One good thing that came of the exercise though is the spacer I designed to be able to receive the cut end of the spring and provide a flat landing at the other side of it. The spacer matches the angle of the spring in its relaxed state and collects the end of the cut spring perpendicular to its winding. This gives the whole first coil and the end support. I will use this moving forward.
Now I will start experimenting with cutting out the tight windings completely and work out some suitable spring rates by cutting out a certain amount of coils (and calculate for a suitable amount of initial preload as well).