Krenovian

Anyone using the Niner Biocentric version 2 eccentric bottom bracket? If so what’s been your experience with it? How easy or hard is it to adjust compared to the Bushnell Lightweight EBB?

OneIsAllYouNeed

The Niner Biocentric fits somewhat obscure frames with 55mm shells. The Bushnell fits 54mm shells. Bushnell offers (offered?) a shim for 55 or 57mm bottom bracket shells. It's worth noting that Problem Solvers currently sells the Bushnell eccentrics. I haven't put enough hours on a Bushnell to comment.

I have first-hand experience with a few other eccentrics that sandwich the BB shell like the Niner Biocentric does. In practice, they're very easy to adjust. I haven't noticed any sticking or seizing issues that are common on wedge-type eccentrics. One of the sandwich-type eccentrics I've used had a bad tendency to "knock" at very high chain tension. I added some soda can shims to that particular eccentric and it's been quiet ever since. I also have a Chinook ultralight eccentric for 30mm crank spindles. Chinook's sandwich-type eccentric which has some adjustable wedges to expand radially, so it doesn't knock like the other one.

Ventana's eccentric is very similar to the Niner Biocentric. Perhaps people can comment on their Ventana or Bushnell eccentric experiences.

Krenovian

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.