When to clean it? When its dirty. Whats dirty? Depends on how picky you are. I ride my bike 3-5 times a week, I probably wash it about every 3 months. But the main reason for the wash is clean the drive train and the wheels. I really couldn't care about the frame luster but I clean it anyway since I'm already there.
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Il faut de l'audace, encore de l'audace, toujours de l'audace
1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1