I'm replacing a Shimano Tiagra rear derailleur because I accidentally stripped one of the bolts. On the website I have 2 options. Short cage and Medium Cage. I'm not sure which one to pick. Which is the one that suits the following bike specs that I have on my Specialized Secteur;


Crankset Shimano Tiagra
Chainrings 50/34
Front Derailleur Shimano Tiagra
Rear Derailleur Shimano Tiagra
Rear Cogs Shimano Tiagra, 10-speed: 12-30
Shifter: Shiamno Tiagra



Thanks for your help!