2013 Tiagra RD cassette options
 

I read this on bike rumors:

New Wide Range Road Drivetrains

Most likely in an attempt to gain some of the market interested in Sram’s WiFLi wide gear range drive trains, Shimano will be offering performance and recreational set ups with wider range gear ratios accommodated by new rear derailleurs. Depending on the model, cassettes will now be offered with 30 and 32 tooth large cogs.

Ultegra 6700 – now includes short and mid cage rear derailleur options that accommodate 30T cassettes and in addition, a new 12-30T Ultegra cassette will now be added.

Shimano 105 – now includes 10-speed rear derailleurs supporting 30T compatibility (short cage) and 32T cassettes (mid cage).

Tiagra - now includes 10-speed rear derailleurs supporting 30T compatibility (short cage) and 32T cassettes (mid cage).

Has anyone confirmed that a 11-32 cassette will work with a Tiagra mid cage, and how can I tell if I have a mid cage? I have a 2013 caadx Tiagra. Thanks

You've always been able to get away with 1-2T past the official Shimano spec. If Shimano starts supporting 32T on their mid-cage derailleurs you can probably run a 34T cassette no problemo. Most OEM road bikes come with the short cage rear derailleurs so you may need to buy the mid-cage derailleur separately if you want to run shorter gearing.

Look for the P/N stamped on your rear derailleur. GS=mid cage. If you're not sure, just google the P/N to find your answer.

Thanks. Mine reads:

RD-4600
Japan VA

no "GS" anywhere. Has anyone successively installed a 11-32 cassette on a short cage?