Backhoe Video: How deep can you dig?

[KWentling]

I have a BX22. When I built my 9" bucket I had determined about 8" was the absolute minimum width the bucket could be without the bucket linkage rubbing the side of the ditch. Those pins are about 7 1/2" long. I wonder what the actual width of the ditch dug in that video is? My main goal when I built the bucket was reducing the cutting force needed to get through our clay that gets about like rock when its dry. I bought the rig with the 12" bucket, which gets little use now unless its wet or I need a hole to work in. If it truly is a 4 1/2" ditch, is the bucket linkage changed also? Looks like a nicely made attachment.

Kim