Will a 105 M7000 RD work (indexed) using 8sp shifter, and 8 sp cassette & chain?

[Retrorockit]

IDK if the road 11s and MTB 11s are the same. But MTB stuff works just fine.
The HG11 road spline is wider, but the cassette width is the same because the 11s MTB is dished in the back. So a cassette spacer will be needed for road hubs.
11s Shimano MTB, and all SRAM use the same cable pull. The ZeeRD M640 gets an SS cage derailleur in 11-28, or 11-36 capacity. I';ve used up to 11-40t.. Then SRAM 1:1 Shifters. I used a Deore 11s derailleur 8s cassette, and SRAM 1/2 pipe shifter together. Since you're taking 105 you're probably drop bars. I have no experience with those shifters, so I'm not usre what's going on there, but I would see what SRAM uses.

 

[79stef]

This for anyone interested in mullet gearing

https://www.scribd.com/document/392...nce-Behind-the-Magic-Drivetrain-Compatibility

Just multiply the shifter cable pull by the derailleur shift ratio to get the cog pitch and the jobs a good'un. Basically; if the sum does not equal any available cog pitch( or at least within a tiny part of a millimeter) then that combo will not work.

Have fun.

A useful tool! Thank you @Frankenorange