Just slide on to it; come in fast and start sliding a few feet before the jump, like you're turning 90 and sliding to a stop. You'll ride right up on it like nothing. I was doing it last night on a buried up-to-flat kinked rail, and it was initially a bit weird, but after you get used to it it's almost easier than jumping onto a rail.
--Disgruntled and Nostalgic Crazed Posting Bro!--