Had that problem; it was a sad surprise and I thought that I'd considered everything!
My only resolution was to nicely trim ( with snips) the top 2" of the plastic drop-in trashcan (that drops into the wire pullout) only at the back half, in order to clear the sink. It still works fine, and frankly, I can't think of any other answer. I still can use tall trash bags too.

Thanks... which sink do you have?

Is this problem with all Silgranit undermount sinks? I am putting in a 24 inch with (now I hope!)a trash pull-out. I should know either this week or next.

not a silgranit specific problem, just with the deep sinks in general sometimes there's not enough clearance so I was hoping to hear from those who've done it before I order specific cabinet sizes and the sink.

I have the 1 3/4 Silgranite in Anthracite.

I thought I had thought of everthing but when my husband went to hook up my sink because of the design of my sink base and the deepness of sink there was no room to hook up GD! Had we known this before he could have easily re-routed pipes. Instead we had to call a plumber to cut a hole in the wall. $400 later I have my blanco cascade sink. I'm not trying to discourage you just want to save you the hassle and expense to plan better than I did.

Thanks, marybeth1