whats the deal with some bars not being knurled? will they totally slip? just curious cuz i got some repro kos bars....non knurled. its for a 26" so i'll probably just be cruising and doing wheelies. anyone ever take bars to get knurled at a machine shop....or not necessary? thanks.

Knurling is great, but not necessary. Slippage is usually due to the handlebars being poor quality, or too small for the stem. If your bars have small diameter tubing, or if they're weak enough to get crushed in the stem, then the stem clamp will "bottom out" and your bars will slip.

When I was a kid, the stock mild steel bars on my Team Murray slipped every time I landed from a jump. As soon as I replaced them with GT pro bars--which had high quality, larger diameter chromoly tubing--the problem was solved forever.