history repeats itself again, and I learn something new everyday

Today at the shop, right before close, some semi-regular neighborhood guy walked in with his early 1990s Gary Fisher mountain bike, complaining of symptoms that suggested a broken bottom bracket (BB) spindle. I grabbed the cranks to see if they'd spin independently. They didn't, but there was the sensation of bearings binding and the BB spindle precessed significantly. Hmmm. I noticed and mentioned that the BB shell seemed wider than normal, and that the BB retaining ring(s) seemed farther inboard than normal. M removed the crank, and voiced some confusion and/or displeasure at what he was seeing. Where we'd normally find some kind of BB tool interface, there was a snap-ring. Ok, weird. M produced a tool I didn't know we had, and removed a snap-ring from each side of the BB shell. Then he used a hammer to drive out the spindle and bearings, one of which was in pieces, and the source of the initial problem.

This is the entire BB assembly, including the broken bearing:


And this is the BB shell:

Note the slots for the snap-rings, where, more commonly, we find threads.

The BB shell is about 88.5 mm wide, which is 20.5 mm longer than normal:


Some internet research revealed a couple bike forum discussions of these unusual BBs, but information was sparse, at best. It seems to have been branded by Gary Fisher with the term "Evolution" and some called it "Extra Wide". The spindle was not branded with a Shimano or Sugino logo, but with a Gary Fisher logo, suggesting this was a proprietary, Gary Fisher component, though M thinks Klein had something similar or identical. In any case, it actually seems like a pretty clever design. The extra width and larger bearings would seem to make for a stronger, and less flexy BB. And since there is no need to have threaded cups and/or a BB cartridge shell, it isn't necessarily much/any heavier. Despite Fisher and Klein getting behind the idea for at least a couple years, it certainly never gained much ground with other brands.

Instead, square taper BBs with skinny spindles but largish bearings, which, with their cottered predecessors, had been the standard as long as anyone can remember, gave way to ISIS and Octalink BBs with fatter spindles and smaller bearings. Then the entire concept of a BB with bearings and a spindle contained within and threaded into the BB shell, which had been in use in various forms for many decades, was supplanted with external bearings (still with the standard threading) and cranks that had the spindles attached to the crank spider. This was both lighter and had a large diameter spindle and "wide-stance" bearings for added stiffness/strength. The next step, which is where we are now, is a revisit to press-fit bearings similar to what Fisher and Klein were doing almost two decades ago (without success). Of course, the new BB30 design and similar proprietary designs are not identical to the Fisher that we have in the shop, but the ostensible motivation is the same: to make the BB area stiffer and stronger without adding weight.

Anyway, I was initially not hopeful about this repair, and suspected that the frame was trash since the BB was so oddball. But it turns out that the old Fisher is actually pretty cheap to fix. The wholesale on two new bearings (which are a standard size) is about $5. This was delightful news, but also a little disappointing, as I had designs on the semi-rare 1-1/4" threaded headset and stem on what might have been an otherwise useless frameset (my tandem takes that size headset and stem).