If you want to rank up, just play to the best of your abilities. You're not going to rank up by getting demoted to Bronze.
And I'm inclined to believe you're lying that you don't want easy wins - why the hell else would you want to be put at a lower rank than you're currently at? It stands to reason that you are at the rank you are right now because you are skilled enough to be at that rank. The players less skilled than you are ranked lower: I.E. Bronze.
Even if you're at the very border between Silver and Bronze, you're still playing above Bronze level, so the only reason you would want to be put down to Bronze is so you could play against people who are at Bronze level...I.E., less skilled than you're thus far proven to be.
And even if you aren't lying, there's still the high probability that your plan could backfire. By and large, Supports rely heavily on their team to win - and those teams also rely heavily on the Support. If they can't pull their weight, you lose by default, and if you can't pull your weight, you hinder their ability to pull theirs, and it all comes apart from there.
And since we're talking about players of a lower skill level than you, there's a fair chance that they might not be able to pull their weight, and I doubt even "Carry" Supports, like Brand, Veigar, or Zyra, could really make a difference if everybody else is floundering around.
All said, if you really, really, really want to rank up: Do it. Climb. Do not consider demotion for even a second. Play. Fight. Win. Climb. Don't ask to be force-demoted, don't sweat it if you get demoted normally, just play.