their are four cylindrical rubber pieces that fit into the boxes in the kufens, or runners. The bridge legs slide inside the gummie, which allow the sled to be flexible and the kufens to move up and down Found on http://sports.espn.go.com/oly/winter02/bobsled/feature?id=1302263
their are four cylindrical rubber pieces that fit into the boxes in the kufens, or runners. The bridge legs slide inside the gummie, which allow the sled to be flexible and the kufens to move up and down