Unimpressed

On my last ride, the left crank arm loosened and nearly fell off. Due to the unusual size of the bolt head (10mm), I was unable to adequately retighten it so the last several miles of the ride were less than enjoyable. 

The last 15 years or so has seen a dizzying array of new component standards in the bike industry, some more mechanically successful than others. I’m leaning towards this particular bottom bracket/crank arm standard being one of the less successful ones.