What is the cable pull of Tiagra 4700 10 speed? What is the actuation ratio? It is well documented that Tiagra 4700 is not compatible with other 10 speed parts, and uses a different set of ratios. But what are those ratios?


What is the cable pull of a Tiagra 4700 10 speed shifter (ST-4700-R)?
What is the actuation ratio of a Tiagra 4700 rear derailleur (RD-4700)?




The 4700 cassettes do appear to be compatible with other 10 speed components. 

Shimano provide a compatibility chart, but that is only useful within the Shimano product line. 



Here is my attempt. 

Cable pull * Derailleur shift ratio = Cog pitch


(Supposedly) 4700 uses 11-speed cable pull, which is 2.7
The cog pitch for Shimano 10 speed cassettes is 3.95
So 2.7 * Derailleur shift ratio = 3.95
And we get 1.46296
According to this YouTube video, you can combine:


Shimano Tiagra 4700 shifters
Shimano GRX 812 11 speed rear derailleur
11-34t 10 speed cassette


This implies that a Tiagra 4700 rear derailleur has the same actuation ratio as Shimano 11 speed road rear derailleurs, as suggested by Argenti Apparatus. This is a ratio of 1.4. 3

Plugging these numbers into the equation we get: 

Cable pull * Derailleur shift ratio = Cog pitch
Cable pull * 1.4 = 3.95
Cable pull = 3.95 / 1.4
Cable pull ≈ 2.82


So, to answer the question: 


Tiagra 4700 10 speed shifters have a cable pull of 2.82
Tiagra 4700 rear derailleurs have an actuation ratio of 1.4