Originally Posted by
Al1943
No. The GS road derailleurs have the same large cog size limit as the SS. The difference is the chain wrap capacity (as others have already stated).
Yeah, you're right. I stand corrected on the road line of Shimano. I'm confusing Mtn with Road where Mtb 'GS' has larger sprocket support and road components need an "SGS" (extra S) designation to indicate larger sprocket support. The 105GS only has 28t max just like the SS. Must be for a perceived cyclo-cross market. I'm so behind the times!