From: "r cielec" <email@example.com>
> I have a pair of 27 ins. Weinmann concave clincher rims. I noticed the rims have no hook for the tyre bead and don't recall ever owning a hookless clincher rim.
> What do I need to know for safe tyre mounting and use?
Richard, Maybe you missed my post to the BOB list:
"I'm running three sets of concave rims and have seemed to put the problems behind me. Biggest problem is too high a pressure. I've found that I need to run a tire of sufficient size so that I don't have to max out the pressure to support my weight. (I'm 230 lb and if you're 150 and think this stuff doesn't matter quit reading now) That means 700x28mm for me, but I shouldn't have to go over 110 like I did when running undersized 25 width tires that were really 23 if you measured and had to be pumped hard. (IRC Triathlon) I found an older set of Michelins that measure 30mm actual width. I can run these at 100psi if I want. Also I cleaned the inside of rim with medium scotchbrite pad, degreased, scrubbed tire with soap and water, and used very little talc on tube being careful to keep it off rim and tire bead. This was all get a bit more "tooth" for tire to grip rim. Also watch out for rim tapes as the concaves took a narrow plastic strip that I don't think is made any more. (Grey Kool Stop) In a pinch I use the narrow Velox with electrical tape to protect tube from chaffing on edge of tape. If anyone tells you that can't happen don't believe it. Hope this helps. These rims aren't as evil as some would make them out to be."