pic: 3CIM Single stage shifter

[Nuttyman54]

Originally Posted by billbo911

It would be quite simple to replicate spread of the standard VexPro Ball Shifter of 2.27.

The problem is that the reductions you get from those stages are to small to realistically do a direct chain reduction, so you'd need to add an additional gear stage...at which point you're back at something akin to the available COTS options. You're trading reduction for spread

The stages the OP has modeled are 18:60 and 24:54, which are 3.33 and 2.25 reductions, respectively.

The alternative gearing you propose to get the 2.27 spread (24:60 and 40:44) only give 2.5 and 1.1 reductions, respectively.

You could maybe do a 34:44 reduction instead of the 24:54 reduction, for a 2.57 spread (almost the same as an AndyMark Supershifter), but that still ends up awfully fast (20fps range) with a 12:36 chain reduction.