I have the same problem with my 1980/1 Dawes Galaxy. Which is odd seeing as it's supposed to be a touring bike. I shall have to investigate the suggested solutions. Another option would be a bar mounted cage?
That is bizarre.. IIRC the Routier was also touted as a budget touring bike, but is really just a glorified / stylised generic utility frame and obviously at the other end of the market to the Galaxy. I think a bar-mounted cage would look totally in-keeping with this kind of bike; however in my case bar space is limited and I already have a cage that I'd like to use.
A bit of an update; and welcome break from the past week of sleep-deprived Brompton-facing hyperfocus..
A few weeks ago the bottom bracket started clicking on alternate pedal strokes. This turned out to be because the lockring had become loose, allowing a bit of float in the adjustable side of the BB assy. Unfortunately I was completely devoid of tools for this job so had to wait until I'd sorted some.
After the usual agonising over the available options I opted for a Super-B "unversal hook tool". Since the adjustable side of the BB only needs gently tweaking up to preload the bearings, this can be done using an adjustable spanner (or ideally two 16mm spanners), without removing the pedal..
I managed to get the assy nipped up with no dramas. By its fairly crude nature the hook tool is pretty unstable and care has to be taken to ensure that it's properly aligned with both the notch and circumference of the lockring to prevent it slipping and risking damage to everything involved (including fingers).
I've not had chance to test-ride it yet, but loading up alternate pedals while static with the brakes provoked no noise
On to the bottle mount fiasco; and thanks to the generosity of fellow forum member
@DCBassman these dropped though my door a while ago - thanks Den!
Yesterday I got the chance to fit them and as usual what started off as a two-minute job escilated.. The supplied button head bolts for the cage had too-large-a-head to fit so these were swapped out for some capheads I had lying around. The rubber inserts were too long for my skinny tubes so had to be trimmed to length, while the ends of the straps were a bit tatty so trimmed ever-so slightly to tidy them up.
Unfortunately I managed to scratch the frame with one of the retaining screws I'd fitted since it was projecting from the bottom of one of the mounts and evidently came into contact with the tube while I was tightening the straps. Only a problem cosmetically on an old, cheap frame that already has plenty of battle damage; but irritating all the same.
Anyway, I finally got the mounts on along with the venerable TacX cage that came off my old Giant I bought nearly 20yrs ago. Since the screws that tighten the mounts' straps are plastic you can't get a lot of torque on them before the key slips in the head, but I think I got them sufficiently tight as they seem pretty secure.
Granted, a bit incongruous with the rest of the silver finishing kit, but can't complain for stuff I already had / have been kindly donated.
Looking forward to some accessible refreshment on my next outing on the Routier. Thanks again Den