Originally Posted by
Winfried
To use two chainrings on a gen 3 with a 8-10s cassette, no one in this thread has replaced the Hollowtech with a square taper BB and could tell me the axle length I should get?
In the front, the chainline is ~50mm
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Edit: Would a 122.5mm work for use with a dual chainring?
https://www.birdybicycle.com/product...-foldable-bike
As already said, going back to a square taper is a downgrade.
The square taper is only mounted on the low end Birdy Classic.
If it helps, on my Birdy Titanium, which comes with a front derailleur, its a compact road 52-36 crankset (FSA SLK-Light) equivalent to a
Shimano 105 crankset that cost about 56€ with 50-34 chainrings with a shorter road chain line and it works.
If the external bearings mounted on the Birdy 3 do not fit,
the BBS-RS501 Shimano external bearings for the 105 cost about 13€. The best would be to firts dismount the original crankset to measure its axle diameter.