Reviving an old thread... I did upgrade the horn on my motorcycle. I can say that a horn on a bike is very necessary. This is because motorcycles apparently have cloaking devices that make them invisible to other drivers. I went from a stock single low tone horn to a high and low horn module. The difference is amazing! I used a relay to get power directly from the battery.
Went from this... (click for video)
to this... (click for video)
