Hmm, what to do when your recycled old commuter doesn’t have fittings for a bidon cage?
Well, I found this Tioga brand handlebar mounted one in a local bike shop (LBS) – but in black… anyway, I bought it .
I was hoping for plain alloy to match the road king’s other shiny fittings and brown tones…also, on its first use the bottle bounced out on a big bump and nearly smashed due to the loose fit and springiness in this cage.
My solution was to twine it, not that it was a neat or easy job, but here goes :

as it was – black and springy

taped, twined and starting to shellac

ta daa! — rough’n'ready damping

at last – a bottle in front of me that stays put
The job was done with two single pieces of twine, and the hardest part was to finish the winding so that the twine ends don’t unravel off the double sided tape when first wet with shellac, and also to negotiate the many changes in radius of the curved shape without leaving gaps…
I cheated somewhat by clamping the ends with a bulldog clip after shellacking, then recoating gently when dry, and finally putting a spot of clear epoxy on it, just in case!
I feel that if I did another of these I could improve on this one, but am generally happy with the result. It matches the twined kickstand fairly well.
Perhaps it’s otherwise easier to twine the bottle?