But going on perfection--I am very particulalr about how I set up my bike and have even taken to marking the seat post and bar angle so I get it right if it changes. 1/4" out on saddle height and I know it. Wheels slightly out of true and I can feel it. But I work to within 1/4"--Others I know measure in 1/2 mm's. Thats the difference of putting a pair of tights on for a ride.