I did a search for “bar ends” to see if someone had suggested this before. I apologize if this has been posted previously.
I have the GB handle on my Coker, and have been watching the evolution of various handles by several members of the forum. I installed new Cane Creek Ergo bar ends on my mountain bike, and decided to try the old CODA (Cannondale) bar ends on the Coker. They attach to the ends of the GB handle nicely at a 90-degree angle, and provide the extra hand positions I was seeking. Most any bar end would work, just experiment with them as far as left/right positioning.