Hello, i have got some echo cnc 7057 cranks with tensile free wheel and echo bash, and have fitted them onto a fsa bottom bracket, but i tighten the cranks and they come loose, and the left crank arm (non drive side) you can atcherly wobble it from side to side and is loose even when i have tighten it as tight as it will do i was wondering if it is cranks or my bb that need replacing? Thanks liam .