Originally Posted by
1989Pre
I'm learning along with you, because I bought a Claud Butler yesterday on Craig's List, and I was surprised to find that the rims were 27" Super Champion Gentleman. More-surprising-yet was that the rear rim is schraeder. Velobase says they built them both ways. The tube inside the rear tire is a CST from China, and seems very substantial. Not sure I want to ride with such a heavy tube if I have a tire with puncture protection.
It's hard for me to imagine such a narrow rim's designer even thinking about blowing that big of a hole through both walls of such a rim, so I'm thinking that it was a concession made to those who were marketing these rims to, shall I say, "stubborn and/or pragmatic Yanks", likely as a marketing-pushed "manufacturing variance" issued some time after these rims were designed.
The discussion probably centered on the pragmatic view that "the consumer is going to drill them anyway".
Some tubes, especially Shraeder tubes, already have difficulty seating their stem reinforcement pad between the beads of tires mounted on such narrow rims. Ruptures (or the tell-tale stretch marks) of the tube just to either side (along the rim) of the reinforced area are common to find on tubes mounted to such narrow rims, as the air pressure alone may not fully seat the valve stem's reinforcement in the rim cavity.
To be sure though, the Gentleman
was just a bit wider and stronger than comparable narrow rims made by Mavic and other competitors.