Bolt Circle Diameter

My take? The best BCD is 50.4/80BCD like the vintage TA Cyclotourist, and Stronglight 49D. Those are jim dandy, but opt for one with a standard JIS extractor like the offerings from Velo Orange, SunXCD or vintage Sugino (PX and Super Maxy) and others. I welcome more narrow-wide chainring offerings (at the time of writing, the only know such ring is a TA 38T, available from Cyclodonia in France or I’s in Japan).

Why 50.4/80BCD? This pair allows a wide range of tooth counts, including some very small and large rings, but at prices less dear than the (very, very nice) Rene Herse 3-bolt and the White Industries VBC cranks. And I think they’re beautiful.

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