Sometimes a goal can be a motivator. The key is picking the right goal. Sounds like you're using distance as a measure - both total miles and miles per ride. Perhaps a weekly total would make sense?
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A conclusion is the place where you got tired of thinking. - S. Wright
Favorite rides in the stable: Indy Fab CJ Ti - Colnago MXL - S-Works Roubaix - Habanero Team Issue - Jamis Eclipse carbon/831