I've asked this on every forum related to every bike I've ever owned. I know that, on these locknut and tappet headed bikes, it says to check the clearances every 4k miles. I would imagine that interval is longer on the shim-type heads. Do any of your tappet-style valves actually require adjustment every 4k miles? I guess I should ask...Does anyone ride their bike hard enough that their valves actually need adjustment every 4k. I did mine 2k ago, and they are still clicking away loud as ever. It doesn't sound like the clearances have changed at all. Any thoughts?