Joined: Jan 2009
Posts: 44,340
Likes: 6,640
From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
[MENTION=71944]e0richt[/MENTION], that just means your flash's intensity isn't sufficiently greater than the intensity of the steady mode. I don't know if that matters, but I guess it means you're wasting power for a marginal effect.
My main commuting bike has two tail lights, one steady and one flashing. This way, I hedge my bets as to which works better. I might be wasting energy, too, but it's not much.