SRAM cable spool for Shimano 12-speed cassettes

This is a variation of a cable spool for SRAM road bike shifters. It is like the original SRAM cable spool, but is a little bit smaller in diameter to pull less cable, therefore move the derailleur a bit less.

The spacing between cogs on a Shimano 12-speed cassette is a little less than the spacing of a SRAM 12-speed cassette. This should make a 12-speed SRAM shifter work better with a Shimano cassette. It won't necessarily work perfectly. Note: I have heard that SRAM AXS 12-speed cassettes have uneven cog to cog spacing, so this might not work well with the road 12 speed gear ratchet. It might work better with the mountain 12 speed ratchet on an Exact Actuation derailleur without the replacement fin.

There are two variations:

• One that is like the original cable spool, but with a valley formed in it at the proper diameter. That should be labeled v13.
• The other is the smooth on the circumference because the perimeter above the valley has been removed. v14.

Both have slightly oversized holes to compensate for my 3D printer making holes too small. In the Fusion 360 part file, set the KludgeFlag to zero to make the holes normal size.

My recommendation is to use the latter because sometimes the cable doesn't lie flat in the valley, but instead gets caught on the 3D print and climbs the walls a bit. That increases the cable pull and throws off the shifting more than if the cable just wandered side to side on the flat spool.

I have left the version with the valley for continuity with the project this is remixed from. That project didn't have any issues with the cable climbing the walls, but that may because they were tall enough and steep enough, or I had a better behaved cable.

Make sure to use a new, high quality shift cable. One that has been reused a number of times often takes a set and stays twisted by the cable spool. If it doesn't get put back in the same way, it can also not stay centered on the cable spool, especially as it gets wound more in the lower gears.

This has not been tested because I have a different kind of SRAM 12-speed shifter and my Shimano 12-speed cassette is still on backorder. I am open to any feedback for improvements to this part, and obviously people are welcome to modify the attached Fusion 360 file. Further information about it can be found in the project this is remixed from.