adapts a 110bcd road chainring to the bafang bbs02. The bbshd uses a different bolt circle diameter and center bore(smaller). works with a 36t ring, any smaller and the chain doesn't clear the spider. print flat side down, I used petg and have >500mi on this thing, with >200nm torque with no issues. Mounts with the flat side facing out- the spider is designed so the chainring bolts will clear the reduction gear housing. Uses standard 10mm double chainring bolts. may have to drill the chainring bolt holes out with a 3/8 inch drill- 23/64" works much better. you need washers under the bolt heads and some m5x16 bolts- the stock m5x12 bolts WILL NOT WORK- they are too short as this spider is 8mm thick.
This also enables a better chainline than the stock offset chainrings.
The author hasn't provided the model origin yet.