Thanks for your input David. I appreciate it. I have experience with the Bushnell Lightweight EBB on our current tandem. It gets stuck on occasion and I have to give it a tap with a plastic mallet to get it free. I started looking into the sandwich style EBBs as I’m considering having a travel tandem with couplers built and I’d like to have an EBB which wouldn’t require carrying a mallet to free it up should it get stuck while disassembling the bike.. I’ll look at the Chinook and the Ventana EBBs. The 55mm ID shell requirement of the Niner Bio-Centric probably makes it a nonstarter.