Welcome to the forum!

I believe something that will tell you cadence will help you a lot, but without a computer, you would have to ride solely on effort. You can map your ride on mapmyride or ridewithgps, use a stopwatch, and then calculate speed afterwards and try to beat it everytime you go around that loop also.

Try training and nutrition as well for help: http://www.bikeforums.net/forumdispl...-amp-Nutrition