It’s Eccentric
Monday December 21st 2009, 11:16 am
Filed under: Observational Review

The other day we got a Niner in the shop for a customer. We were all stoked on it, appreciating it’s quality 853 steel construction, nice flake in the paint, and the curve of it’s stays. I had the benefit of assembling it for the customer who had ordered this S.I.R. 9. The website shows a lot of the bike’s attributes, which you can see yourself. I particularly liked some of the company’s “attitude” on the frame, especially the top tube decal: “Pedal Damn It”. The option of running this model as either single- or multi-speeds, with the inclusion of two swappable drop-outs—one with a derailleur hanger—is a nice touch. Part of this frameset included Niner’s own eccentric bottom bracket, dubbed the Bio-Centric.

They seem confident in this Bio-Centric eccentric bottom bracket, but they may have been the only ones the day that bike was put together. Initially and instinctively, I greased the aluminum bottom bracket assembly before installing it in the frame. Greasing the system was immediately deemed incorrect, as there was no way the eccentric would remain in a locked position. Like all good mechanics (wink, wink), I searched for the instructions after assembling the component (found here—PDF link). None were included unfortunately with the frame, I needed to download them from their website. (You’d think if this design was so revolutionary, new, and it’s installation so critical, specific directions would be included with the component). Reading the instructions I learned that the assembly needed to be completely degreased and roughed up with sand-paper, (after roughing it up, I gave it a good cussing out too). The directions then stressed the importance of proper installation with—and here was the shocker to me—teflon tape.

Hey, they have colors too! Image courtesy of WiseRacer Sports.

There is this write-up (actually it’s the same as Niner’s site) that describes how the Bio-Centric is supposed to prevent rounding out the bottom bracket shell. While it does tout the Bio-Centric’s benefits in a pretty convincing light, curious however is the complete lack of mentioning the teflon tape. (Same omission on the videos on Niner’s site). Relying on two layers of teflon tape to keep pedaling and vibratory forces from loosening that smooth aluminum surface around a smooth steel surface just doesn’t seem like enough. The Niner website speaks to their “revolutionary” system as eliminating oval-ized BB-shells and stripped parts and creaking, but isn’t teflon tape attacking those problems in a somewhat flimsy manner? I suspect the bean-counters got in on this component’s design, and sometimes, their advice just doesn’t work out as well as it sounds.

Eccentric Bottom Brackets, hmmm, agreeably a great problem-solving component. These seem reputable enough: Bushnell (which Salsa uses),  Carver (also expansion), and others (er… wow); the so-called “problems” plaguing these designs seems to be a matter of operator error. Niner’s description to me sounds like their biggest focus was on eliminating the creak, a general problem I often find is solved by proper installation and lubrication. Like I said, it’s just a matter of confidence, and teflon tape doesn’t inspire much in my mind unfortunately. Have I ridden it extensively? No. Has it slipped on the bike’s new owner? Not sure. Do I think it will? Again, not sure either way. We’ll have to believe that Niner’s testing proved sound—I look forward to my apprehensions proved wrong. I’m not here selling Niner EBB’s or any other type for that matter, I’m really just curious about the subject is all, and writing this up hopefully brings light to a system that initially seems dubious. Hopefully we’ll have a satisfied customer for a long time on their Niner.


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