So we have two basically the same looking and working derailleurs: Shimano u6000 and m5100. They have different pull ratios. The question is if friction shifter would allow me to mix "old" Deore derailleur with "new" Cues cassette?
The cassette is what has the most new features from new groupset (the durability, because it's thicker and made of steel, as well Shimano says that it shifts smoother for some reason).
So the final combo would be friction shifter + rd-m5100 + cs-lg400 (11-51t).
Friction shifting is the glue that may allow this to work.
Since the pull ratios are all different, there's no way to get it working with parts from different groupsets. Your only option would be all 11 speed, or all CUES.
Your rear derailleur has to have enough horizontal movement to cover the whole width of the cassette but not hit it.
The one potential downside I see is that 11 speed chain is narrow, so you won't get a lot of "tolerance" on the shifter position. It may feel twitchy and hard to settle onto a specific cog in the cassette.
Also, without a good firm level of friction/resistance, the wire may move subtly to put you out of gear (though this is a general setup thing for any friction shifter)
Technically yes, but if the amount of travel allowed by the shifter is not sufficient you won’t be able to access all gears. But the experience is unlikely to be better than an indexed system.
That being said the u6000 derailleur costs more or less the same as one m5100 cassette, so its cost will be recovered “fast” - depends how often you need to replace them, but mid drive e-bikes eat the small sprockets quite fast. So why not change the shifter and the derailleur as well to have a full cues system?
Old thread, but I will add. To my knowledge, M5100 is a Shimano MTB 11 speed and the pull ratio is 1.1. All CUES have a pull ratio of 1.13, which is neglectable and all 11 speed SIS MTB shifters will be absolutely compatible. Not convinced? Consider the fact that Shimano M5120 10/11 speed MTB derraileur has a pull ratio of 1.15 and Shimano has no problem selling this for either 10 speed MTB (pull ratio 1.2) or 11 speed MTB (pull ratio 1.1). So if the manufacture thinks 0.05 difference in the pull ratio does not matter, the 0.03 difference should matter even less. Knowing this, opens a chest of opportunities, i.e. Microshift Sword or Advent X 10 speed drop bar levers + CUES 2x11 U6020 rear mech + CUES 40-26 crankset + CUES front mech + 10 speed 11-46 cassette + 11 speed chain :)))) This combo provides the widest drop bar range EVER of 640% and is the best possible combo for drop bar thick tire MTB.
