Panhead Duo-Glide Auxiliary Rear Lighting | Under-Seat Bullet Light Mount, Part 1 | Riding Vintage

Panhead Duo-Glide Auxiliary Rear Lighting, Part 1

The stock taillight on my 1964 Harley-Davidson FLH Duo-Glide can disappear into modern traffic after dark, even on a bike that has already been upgraded to a 12-volt electrical system. This Panhead Tech project starts with the old rear fender light bar that came with my bike and follows the first mockup for moving two vintage bullet lights under the solo seat.

This project continues in Part 2, making the rear auxiliary lighting brackets, and Part 3, wiring the auxiliary rear lights.

Starting With the Old Rear Light Bar

Even though my bike has been upgraded to a 12 volt electrical system, the rear taillight still does not put out enough light to make the bike stand out from other highway traffic on a busy night. I’ve seen several vintage riders who have added a pair of red bullet lights under their solo seat and this really seems to make a difference after dark. The original owner must have been worried about this as well, because there was a light bar mounted on the rear fender with six additional running lights.

The original rear fender light bar carried six extra running lights before I removed it from the Duo-Glide.

Breaking Down the Bullet Lights

Although it was kinda a cool vintage piece, I really didn’t like the looks of it and pulled it off the first week I owned the bike. Like everything else I’ve removed, I left it on the shelf just in case I needed it for parts. Well it turns out that the small bullet lights on that light bar are just what I needed for mounting under my seat, so I unbolted a pair and broke them down.

A pair of small bullet lights from the old light bar were broken down for the new under-seat setup.

Checking the Solo Seat T-Bar

Next I sized up some possible mounting points on the T-bar under the solo seat. My goal was not to drill in new holes in the T-bar.

The front bolt on the solo seat T-bar looked like a possible mounting point before test fitting.

It looked like I might be able to remove the front bolt on the buddy spring bracket and just replace it with the mounting bolt for the light. Off came the seat for a test fit.

With the seat removed, the bullet light could be test fit against the front buddy spring bracket bolt location.

Moving the Light Inboard

The light fit OK, but there was no clearance for the bolt that attaches the seat to the T-bar. Looks like I’ll have to mount the light inboard of the buddy spring bracket. I went ahead and attached the buddy spring to check for clearance. Everything looks like it will fit this time.

Moving the light inboard of the buddy spring bracket provided the clearance the seat bolt needed.

Next Step: Offset Brackets

Now I just need to cut a set of brackets to offset the light two inches from the buddy spring bracket.

The final mockup showed that a bracket would need to offset the light two inches from the buddy spring bracket.