Originally Posted by
Bezalel
When staying within the same road groupset, short cage is for a double and medium cage is for a triple. In the change from 9 speed to 10 speed the capacity of the Tiagra groupset has been increased so when using a 30T cog it would be incompatible with almost all previous generation road derailleurs.
I'm running a double chain ring in the front with 10 gears in the back, the specs are as follows;
Crankset Shimano Tiara
Chainrings 50/34
Front Derailleur Shimano Tiagra
Rear Derailleur Shimano Tiagra
Rear Cogs Shimano Tiagra, 10-speed: 12-30
Shifter: Shiamno Tiagra
Would I need a short or medium ring cage?