T Man thanks for the heads up ref being made by Natl. Cycles
Careful if your ordering new.

You need to relocate your signal lights onto a light bar so you can use the signal light mounts as the top supports for the lowers. National cycle designed the lowers that way so they could sell they're light bar along with the lowers.
I got my set from a member here brand new. He didn't tell me I would need the light bar

, which is most likely what he found out after he originally purchased them

.
I haven't spent the time, but it shouldn't be tough to get a clamp of sorts for the top.