Originally Posted by cyccommute

You can solve one problem with the extenders but created others that are far worse. One of the reasons that touring bikes have such long chainstays is to keep the panniers out of the way of your feet and keep much of the rear load either centered over the rear axle or slightly in front of it. Cantilevering a load beyond the rear axle with the rack extenders puts the load behind the rear axle and can lead to handling issues on many bikes. It also leads to a lightening of the front end. The tail starts to wag the dog, so to speak. This effect is particularly noticeable on high speed downhills where the front end of the bike can wobble. High speed and wobble is not a good thing!