Hi all! I found an easier option for more light for my F- model: a direct replacement bulb with a 2100-lumen Osram Rallye bulb (stock is 1400 lm). I googled Candlepower.com and talked to Kenny. Apparently the dual filament H4 is no longer available so a Vosla H4 +100 bulb is now available for you naked gixus riders. On the f-model the bulbs are easily accessed by removing the "meter panels." I received the pair of bulbs in three days and paid under $45 US dollars(including shipping). The H4 is just over half that. Haven't been to my Lake ride yet (monsoon weather), but wheeled it out last night just to check light output and was pleased as it illuminates my neighbor's house clear across two cul de'sacs .