An expandable seal has at least one travel stop designed to engage the surrounding tubular to limit expansion of the ring shape of the seal and in so doing limit the stress of circumferential ribs that extend from the ring base shape as they engage the surrounding tubular. The travel stop can be a solid ring or segments and can have a rounded outer surface designed to engage the surrounding tubular in a flush relationship. Alternatively the outer surface can also have hardened particles for a bite into the wall of the surrounding tubular before the blunt portions of the travel stop come into contact with the inside wall of the surrounding tubular.