I have a Whispbar Rail or FlushBar how do the sizes compare to the Yakima Flush or RailBar? Dave Dezellem Updated July 21, 2017 17:30 Follow To see what the size conversion is between Whispbar and Yakima Rail or Flush bars please see the attached PDF. Whispbar-Yakima bar conversion chart- with SKUs.pdf 800 KB Download Related articles Why can't I find any Whispbar fits? M-Measurements The CrossBars that Yakima recommended for my vehicle seem really long. Can I cut them down to length? My rack is making noise, what can I do? How does the Yakima BedRock attach to my bed rail? Comments 0 comments Please sign in to leave a comment.