Originally Posted by brooklyn_bike

for what it's worth : i had them same problem with my existing 12mm allen wrench. i read someone's older BF post with the same problem and he tried a different 12mm and it fit perfect!? so i went to the local pawn shop where they have a big bin of allen wrenches and brought the wheel with me. the first one i grabbed and test fit - fit perfectly!? just a weird happenstance certain 12mm seem to fit better. not sure i ever figured out why but i bought the other allen wrench just in case i ever needed again. cost .50 cents