Need to separate some wheat from the chafe on this.
The rim failed at the tire flange, so more or beefier spokes will have zero effect. Then you mention disc brakes, which if you always had them, means that brake wear isn't the cause. Even if you were using calipers I don't know if various rims have thicker tire flanges.
So if you want a rim that won't fail the same way you have to analyze the actual cause of the failure, which I suspect is chronic over-inflation of the tires, possibly combined with too large a section for the rims.
Before you say that you don't over-inflate, consider that the max pressure molded into tires only relates to the tire's strength. But with wired -on (clincher) tires the rim itself is part of the pressure vessel, and the flanges have to hold against the outward pull of the beads. Applying the formula for hoop stress of pressure vessels, we find that that the stress on the flanges is proportional to both the pressure and cross-section diameter of the tire. So at the same pressure a 45mm tire stresses the rim flange almost twice as much as a 23mm tire.
Rim makers are weight conscious so tend to design their rims carefully around the expected tire section and pressure, and not leave much room for error. If the rim is designed around a 95psi 25mm tire, you have to be careful about max pressure of larger tires.
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FB
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Last edited by FBinNY; 03-09-11 at 05:32 PM.