I plan on competing in Time Trials in the spring and I have built my TT bike and have been contemplating using disks but not sure if it would be worth the investment. I know they may add an extra pound but not sure if the areo would make up for it. I said that about the areo helmet but purchased one anyway. It made a significant difference especially on windy day. What are your thoughts? Right now I am riding 23 miles an hour for 10 miles and 20 -21 miles an hour for 20 miles. Just giving you an idea of my level of training and level. I know this is a road bike forum (which I also do) but not having much luck with the triathalon folks. Any input would be appreciated.