I have a Whispbar Rail or FlushBar how do the sizes compare to the Yakima Flush or RailBar? Dave Updated April 12, 2018 20:27 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 CrossBar Options The CrossBars that Yakima recommended for my vehicle seem really long. Can I cut them down to length? Rack is making noise Comments 0 comments Please sign in to leave a comment.