I need a new upper pulley/jockey wheel for my 2005 10sp. Ultegra derailler. I was thinking of aftermarket and found theseand though they were pretty cool. I searched around and it seems like most are 11 teeth for the 10 speed compatible. Is there a problem with shifting if I use these 12 tooth wheels? I'm more concerned with smooth shifts and losing any grams from such a small part.