OK, works here if we add a brief delay to ensure that front document
is already bound to the document of the new window.
tell application "Bike"
activate
set bikeurl to URL of selection row of front document
tell application "System Events"
tell process "Bike" to click menu item ¬
"New Window" of menu "File" of menu bar 1
end tell
delay 0.1
tell front document to open location bikeurl
end tell