If I can find a compatible threaded suspension fork with disc brake mounts, that'd be a way to reduce new rims purchases, and install one hydraulic disc brake to my Helios. The one I have found so far has no disc brake mounting point. Looks similar to this but older:
I'll make enquiries with the Dahon expert dudes CH White and his Son re: Dahon's own new suspension forks - this one reportedly doesn't last very long, but later versions have disc brake mounts. Rare and not cheap.
This is patented but not available. No disc brake.
https://www.cyclemotion.co.uk/dahon/Dahon_2004/uniflex.htm
Thanks for the info regarding the Dawes Jack - seems fitting a front suspension fork with lockout on that is viable? Perhaps the Argos folder too? I found a threaded sprung suspension fork which looks compatible with my Dahon, but I'd try swapping out my 1.75" Schwalbe Marathan Plus for Big Ben Plus 2.125" wide tyres first, if necessary.
My enquiry was related to saving rims - if I ever got around to a hub motor conversion, I'd prefer a steel frame. Does Dawes only make aluminium alloy framed bikes now? I'd have to find an old Kingpin for steel. Could I fit a Suntour suspension fork and a front disc brake to this?
To change gear on the SA I would pedal backwards a little then I could shift the gear easily. Otherwise would be stiff. Brake Pads (these were from my old bike and are much more effective than the ones originally on the bike).
www.ebay.co.uk
I'm not after a bike to convert to a hub motor system at the moment. I'm deliriously happy with my hill devouring 20" wheeled Bafang Dahon Helios P8 BBS01B mid-drive folding bike conversion, and don't need another ebike. But rim purchase reduction would be nice.