An umbrella frame provides a stable and enduring support for an umbrella canopy while also allowing canopies of varying shapes and sizes to be mounted thereto. The umbrella frame includes a hub assembly, namely, a main hub member mounted about a central pole member of the umbrella frame which offers improved means for attaching brackets thereto which are structured to pivotally receive a plurality of strut members therein, which strut members are, in turn, pivotally secured to a plurality of rib members interconnected with an upper, secondary hub. The main hub member of the present invention preferably includes an upper portion, a lower portion, and a channel having at least one ledge formed therebetween, with a band formed from a flattened strip of metal secured within the channel about the hub member. The channel is formed to have the same general height dimension as the brackets, which are secured to the band and the hub member and are confined within the space defined by the channel so as to prevent rotation or twisting thereof. As such, the present invention provides for an umbrella frame which is more sturdy and durable and yet, which allows the size and shape of the attached canopy to be readily varied.