Originally Posted by roccobike

I have two sets of Araya and one set of UKAI 27" rims downstairs. They are all more or less designed the way you have drawn. Only the Araya 1" rims on my Nishiki Custom Sport have a true hooked bead, similiar to a Mavic 700C rim (I had handy). This subject came up in a previous thread. Someone explained that some of the early 27" rims do not have the pronounced hook like newer rims have. The highest pressure I've run was 105PSI on 1 1/8 Performance Forte non-folding tires on these 27" rims. I've never had a blow-out or had a tire jump the bead using rims with that bump at the lip. Yes, I've had several tires not have the bead seat when I exceeded 85psi using straight chrome rims.