Trek Allant+ 8S Headlight has a mind of it's own - Flashing/Constant ON.

[offthewall]

My one month old Trek Allant+ 8S headlight seems to be possessed. When I first got the bike, it would only flash on low beam. Then for a couple of weeks, it would be on steady on low beam. Now it's back to flashing only. It does not seem to be ambient light related as I've read elsewhere. Any tips? Something broken?

 

[fooferdoggie]

My one month old Trek Allant+ 8S headlight seems to be possessed. When I first got the bike, it would only flash on low beam. Then for a couple of weeks, it would be on steady on low beam. Now it's back to flashing only. It does not seem to be ambient light related as I've read elsewhere. Any tips? Something broken?

ya mine was a bit weird on flashing for a bit. then it started flashing all the time during the day. but at night I had to hit the high beam and then it would be steady. then back to flashing the next time I rode. its took awhile before if flashed on a regular basis.

 

[3jaycee]

I have same bike. The headlight will flash ONLY if the sun is coming from your back. There is some kind of sensor in the TAIL light that senses this, and signals the headlight to flash (strobe). A safety feature I guess. I figured this out with my own experiment one late afternoon: I aimed my bike directly away from the sun and the head light flashed. Then I turned the bike around (into the sun) and the headlight reverted back to constant "on". The situation perplexed me, too for a couple of years when I read somewhere that this is the light issue explained.

 

[fooferdoggie]

mine always flashes now unless I use the high beam. I had this light put on our tandem and we have high and low beam and no flash.

 

[offthewall]

Still can't figure it out. Most times it doesn't flash, just hi or low steady. Sometimes it flashes on low. It does not seem to be related to ambient light. Remains an annoying mystery.