One of my friends has a 1987 XL600 and we were wondering what can be done to upgrade the suspension easily and cheaply. There are a lot of older XR600 parts for cheap on ebay. For the front: It looks like the fork diameter is the same as the XR600. Is it as easy as replacing the forks? I see two different ways. Go with the early non cartridge forks or the later cartridge units. Can the original XL600 brake and wheel be reused in either senario or does a XR600 wheel and brake need to be used? Are the axle diameters the same? For the rear: Since the XL is drum braked, it seems like keeping that will be a lot less work than upgrading to a disc rear end. Can just the XR600 shock be used, or is it best to use a XR swingarm too. What about the rear wheel. Reuse or is a XR600 one required. Which years of a XR600 rear parts fit?