I own Firefox Rapide 21s, which has Acera 7s(14-28t) groupset are rear and Tourney 3s(28-38-48t) groupset at front.
In a recent accident, the rear derailleur took some impact and is bent now, it doesn't latch on to 7th &1st gear. I went to a mechanic he applied some pressure to make it straight, he said it(method) could potentially make the derailleur straight, and I don't want to spend money in getting a new one.
While coming back home, I tried to shift up to 1st gear to see what happens -- it dug into one of the spokes, locking the tyre, making me fall. Now that spoke is bent and has become loose.
However, the real question is: Now, I don't like the method he has proposed to straighten it. Hence, I have decided to remove all the gears and make it a single speed. My focus always has been higher speed, so I'm thinking of getting 53t×11t(chainring×sprocket). But I'm also thinking - the ratio that setup makes might be a little bit too much for me in all circumstances. Therefore, I was thinking of fitting a double crankset up front(possibly 34-50t or 39-53t) and single sprocket(possibly 12t or 14t, respectively). Or is that even possible?
I goolged and looked at most places, but could find any answer.