Trek oversized front derailleur clamp

Hi,

I am trying to get rid of the original derailleur on a Tek X-caliber bike.

These bikes use 36.2 mm downtubes. They are not 34.9mm!! I measured 3 times.

If anyone has an idea how to mount a fornt derailleur on tghis bike that can shift from 28 to 46 teeth on double front ring setup I would...