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

 

[Retrorockit]

There are companies that make cable ratio converters. Problem Solvers, and Shiftmate are names that come to mind. Road to MTB Shimano are probably common. The cable wraps a round a double pulley with one sheave larger than the other changing the motion.
I own one but I'm waiting for the right 11s shifter to show up. For me it's 1x11 using a 9s Rapid Rise derailleur on a Vintage Mavic (HG11 They had it first) wheelset. The bike already has a Front Freewheel setup.
https://www.jtekengineering.com/shiftmate/
Shiftmate 5 might be the one you want.
Of course a vintage friction shifter will simplify things.

 

[79stef]

There are companies that make cable ratio converters. Problem Solvers, and Shiftmate are names that come to mind. Road to MTB Shimano are probably common. The cable wraps a round a double pulley with one sheave larger than the other changing the motion.
I own one but I'm waiting for the right 11s shifter to show up. For me it's 1x11 using a 9s Rapid Rise derailleur on a Vintage Mavic (HG11 They had it first) wheelset. The bike already has a Front Freewheel setup.
https://www.jtekengineering.com/shiftmate/
Shiftmate 5 might be the one you want.
Of course a vintage friction shifter will simplify things.

Looks like a great little device!
However, I think that seeing as the pull ratio of the 105 M7000 is the the same as the older 8,9 speed MTB Shimano gear, I shouldn't need one