Shimano Tiagra 4700 rear mech specification question

[Trotsky_Vulcan]

I have a technical question regarding the Shimano Tiagra GS rear derailleur….According to Shimano…the maximum small/top cassette sprocket it can handle is 12T (12-30 cassette) but every shop that sells the Tiagra 4700 GS rear derailleur that I have seen says it can handle a 14T top/small cassette sprocket (14-30 cassette)….Which is correct…12T or 14T? Shimano are famous for being a tad conservative on their component specifications…Thanks in advance…the answer will determine which 10 speed cassette I get…12-30 or 14-30…

 

[Jonny69]

It’s not usually the small end it struggles with, it’s usually the big end because it struggles to clear the big cog. It’ll be fine with any cassette down to an 11T at the small end. So either 12-30 or 14-30 will be fine

 

[Trotsky_Vulcan]

It’s not usually the small end it struggles with, it’s usually the big end because it struggles to clear the big cog. It’ll be fine with any cassette down to an 11T at the small end. So either 12-30 or 14-30 will be fine

Thank you…