picture is too small to see.

what's the year and model of your bike? you might be able to look up the tube diameter of your bike to see if it'd work. even if it's a little smaller, i think they make inserts to fit a smaller tube.

but i'm not a wrench by any means of the word. someone like margo from luna is more knowledgeable than i!

also, i'm curious as to why when you move to a hilly place a triple isn't working. just sounds like you'd want a triple if it got hillier