Thanks for the link and for taking the time to answer the question.... But for the majority of us "newbs looking rims" information, looking at all those cross-reference drawings and trying to figure out what this all means is difficult. I certainly don't mean to sound less than ingenuous here, but I wouldn't have a clue as to the differences in the construction other then some are larger or smaller in diameter than others. I probably need to speak to a bike shop and have them educate me on the nuances of the drawings and what they might mean so far as durability and over all performance. The first time I saw one of the drawings I was scratching my head until it dawned on me that these are frontal views of rims and that they show varying sizes and configurations. I'm always open to learning and one day will have a better grasp of the differences and how they equate out to performance, weight variances, materials used in construction and the long term implications of use for a novice range rider.