Recently, mobile computers have become to communicate with each other by using a wireless LAN protocol, for supporting various Internet services. In case that a mobile computer changes a location with high speed, less messages are exchanged between the mobile computer and the Internet. This work proposes a novel routing protocol CB-WSCP for a mobile clustered networks in which mobile computers with almost the same velocity and communication with each other by multihop transmission form a cluster. Here, communication between a cluster and a base station is available while at least one mobile computer in the cluster is within a transmission range of the base station. Hence, it is required to support sporadic communication. For achieving wider bandwidth even though the cluster moves with a high speed, a proposed protocol achieves switching of gateways and updating of routing tables.