.headerimg{
    margin-left: auto;
    margin-right: auto;
}

.jumbotron {
    position: relative;
    background: #000 url("../images/bw-withbike.jpg") center center;
    width: 100%;
    height: 100%;
    min-height: 442px;
    background-size: cover;
    overflow: hidden;
}