Acharya - I don't think there's any sliding or similar ability with the tube that mounts to the chassis. As Mark noted, there are additional holes in the 49" guard version that "might" allow mounting in the 31" but I would check with your Felder rep to clear that up.?Reading this thread tells me you will get the best answer there, so if you do get an answer please enlighten us!?
Sang Luu