just a thought, it was mentioned earlier, but try going up in cog size if you can. 16t is going to be pretty tough to get up and running. i would run at minimum at 17t, if you can find it, online somewhere probably an 18t. im running 53/18.

by getting a larger rear cog you may kill 2 birds with 1 stone. you might avoid having to do any modifications, and you would have a better gear ratio.