There are pinstriping pencils available that claim you can paint right over without harm to the finish. Stabilo is the one that is mentioned most frequently.
3M also sells a fine line tape that is available with pre-cut sections that peel out and used as stencils. Should have enough flex and give to work on a wheel to pinstripe. Have also heard that mounting the wheel on a hub horizontally so that the wheel can spin, get the wheel and apply paint from a brush. The last thing I striped took a while to get the touch (and a fair amount of scotch)on the brush (loading, position, and getting the line width just right) before I had the knack. Prepare to practice and make some mistakes.
Now if I stripe anything that has to be dead on, I use a stencil. The stripe turns out just perfect. No variation in width or thickness.
