Why mess with an industry standard hub diameter? To improve it and to optimize it for smaller wheels, that's why! As a rim gets smaller in size, the bracing angle of the spokes changes. If you lace a standard 100mm hub into a 20" or 16" rim, you end up with spoke bracing angles that are too small, which results in a weaker wheel. To solve this problem, we pioneered the Compact narrow width front hub, which over the years has become a standard in the folding bicycle industry. Our compact hubs are also lighter and allow a more compact fold than a standard 100mm width hub.