Originally Posted by
cycle_maven
Oh- you're in Switzerland! That changes a lot. Before buying a new tire, measure the diameter of your rim- It may be a 622 after all- I didn't think that 630's were ever very common in Europe. Remember that the 622 or 630 diameter is the bead seat diameter, so the rim diameter will be a little more.
The inner tube should fit either diameter.
Well, recall the UK at least had a “lightweight” tire option at least back into the 1950s, the 27 x 1 ¼ “high pressure” up to 90 psi. My 1952 Rudge has those as new, with nice, elegant Dunlop rims which perfectly held the old tires, and perfectly hold a pair of modern Specialized Road Force in that designation - wired beads on rims designed for them. So at least in UK such tires were once avjailable widely enough for folks to use them on daily bikes.
Today? I can’t say.