We like this new product from PKD. If you are not familiar with "cross-over" bars, they offer amplified brake inputs over a standard classic bars that have a single center pulley. This is because the cross-over rig with a pulley on each side uses a nearly 2:1 mechanical advantage to amplify the brake input in the direction of your turns, making the kite more maneuverable.
Rig your kite with the main front lines going to the respective outside leaders on the bar and the brake lines to the respective left and right center leaders. A simple diagram is included to help you unpack the bar and lay out the leaders with everything properly sorted out.
The rig features a center landing handle and a "kite killer" safety wrist strap that lets you dump the entire kite on the brake lines to flag the kite out in an emergency.
The bar measures 21" or about 53.5 cm between leader attachments, making it ideal for most any fixed bridle 4-line kite from about 3m to 6 meters or so.
Other cross-over bars are as much as $150 and some use steel slip-rings in place of real pulleys. An optional D-Loop for use with a harness is available (advanced riders only, please) for about $31 - see related products below.
