I'm not sure if this is normal but i just purchased the Zipp 404 which i love but every time i get out of the saddle and peddle hard the rim walls hit the brake pads. The distance from the pad to the rim are normal and actually the same distance as my other rims when its all set up. I spoke with Zipp and they told me to adjust the preload which i did but either im not doing it correctly or that is just not the problem. I love the wheels and its a shame i cant use them in races since i have this problem until i fix it. Any suggestions are welcomed and since this is my first post on this forum i glad to be here and love all the info i have read for some time now.