Originally Posted by
repechage
these predated folding tires.
these Araya rims built up easier than the Weinmann originals I thought.
the rim shape did add a bit of cross sectional area.
when they were available, they were a 27" rim.
maybe 700c for other markets?
Weinmann touring rims from the early 1970's could be prone to loose diameter tolerances such that the built wheel might not contain even a brand-new wire-bead tire at pressures above 70psi.
The Japanese versions didn't seem to have any such problem.
However, later, narrower, double-walled, semi-hooked Araya rims did not always retain wire or folding tire beads at the 90-100psi that I tried running on them. Seems that aged tire's bead rubber didn't sufficiently engage/grip the semi-circular nubs that passed for bead hooks and I suffered blow-offs at the bottom of steep descents using both wired and folding tires. Luckily those front tires both thumped on the fork leg several times before blowing off, so both times I stayed upright. Btw, those were two different tires on two different front, narrow, Araya rims. Tires were Matrix wired and Specialized or Avocet folding, 700x25 (actually about 21mm) and 23mm, respectively.
Folding tires first appeared around the mid-70's, The Michelin Elan tire and Mavic Module-E rim were apparently made for each other, though only the Mavic rim could be considered a complete success and worthy product.
Rigida followed up with their narrow, bendage-prone 13-19 rim and Super-Champion soon came out with their wider/tougher Gentleman rim. Japanese versions from Araya and Ukai also soon arrived.
All of these narrow rims were double-walled and eyeletted.