Originally Posted by
Duragrouch
OP: If you put a deltech cable (loaded in tension) on it, you'll eliminate the bending load on that hinge joint and place the frame tube and hinge into compression shear on the pin, eliminating a lot of the wobble. Torsion loads into the frame beam, like when climbing standing, will not be affected, but the hinge will be tighter. Any cable must be low-stretch; Steel (like Dahon's), kevlar, or UHMWPE like Spectra, Dyneema, etc. The line must be very taut when unfolded. Photo below is from before I secured the line ends. Knot must not slip, I used 8 bend with kevlar line which I happened to have some, kevlar is slippery so requires a good knot:
Meanwhile I'll search for a Kevlar rope, but how do you keep the tension while tying the 8 bend knot, because don't you have to pull the ends to tighten it, causing slack? What about a $2 turnbuckle with a locking nut?
M4, M5, or M6?
Edit: the Kevlar or dynema ropes are braided so won't they lengthen when the frame bends? What about a stainless steel cable? 2mm or 3mm? Cable and u bolt clamp only $3. Maybe need shrink wrap to protect the frame from gouging.