Knog lights on a 25.4mm seatpost?

they're too weak, the front one is just about enough to be seen by other, only if the battery have enough charge in it.

but the rear is way too weak to be seen by other, it's barely visible from a distance.

spend it on a decent rear light instead that cost the same.

+1

I never realised how shit they were until I saw a mate using one, they really are worthless, the front ones are alright though.