They will hurt what is felt. The bike will still be solid and quick, it will still get up and go as easy as pie. However, you will perceive it as slower, weaker or more tame. But you should notice many positive things like better gas mileage for one! Doing your own work is 99% more cost effective you just have to have the right mindset -either its fun or you don't want to pay for labor- I am both. I think that you will still enjoy the bike with the new sprockets.