actually that stick of gum is very noticeable. Longer cranks, you have to lower the saddle a bit. Often you'll have slightly sore hips the first few rides as you adjust your range of motion in your stroke. 170's for 5'10" seems a little unusual unless you're a sprinter (and/or have a very short femur) and riding crits all the time. I'd guess that if you're climbing alot, you'll have your longer cranks back on in no time.