Simplified Chain Length Measurements for Calibration

Is the vertical alignment of the sprocket is important with this technique?

the chains ‘stretch’ (from clearnce between the pins and links in the chain) and
can be different.

the only reason to want to have teeth at 12 o’clock is for the ease of resetting
the chain (which I find I need to do very regularly), if you don’t have a knon
position that has the sprockets aligned, then you have to align the sprockets,
disconnect the chains from the sled, and feed them out from zero.

even with this, it’s not perfect (I don’t think any current firmware sets the
known position accounting for chain sag/stretch properly), but it hits the ‘good
enough for most people’ criteria.

David Lang