Originally Posted by
John Nolan
I must be missing something: why not use one of the many lights that attach to the seat post?
Not the OP, but seatpost mounted lights are often invisible on my bike with a tent or sleeping pad on the rack behind them.
If that's the O.P.'s setup as well, I used a cargo net to hold the racktop load. That made it possible to use a clip-on light, which would normally be clipped onto a jersey pocket, clipped on the cargo net at the rear of the bike. Alternatively, clipping the light onto a saddle bag with a loop at the rear might be high enough to clear the racktop load.