Ok, I'll explain this best I can, apologies if it's hard to make out: Anyway, the larger the diameter of your wheel, the more leverage available from the rim. True? So effectively, there are greater forces landing on ledges etc with a larger wheel. True? With a rim brake, this is compensated for, as the brake also has more leverage. True? Therefore in theory, as diskbrakes work on rotors of a certain diameter, would they perform better on a smaller rim? I think it would because there is the exact same amount of power available from a disk brake, on whatever wheel its on, but a larger wheel would have more leverage to work against the brake. Am I making sense? Anyone with opinions or greater knowledge please could you learn me! Thanks beforehand, Alun