Daveyk15

Currently have a Shimano 600 EX RD-6207 (1984 -1986) on my vintage Carlton running a 50 X 34 T front and 14 - 24 at the rear. Trouble is the lowest gear wont get me up my local hill and a search on Velobase suggests a maximum chain wrap of 28 T.

So the question is would my short cage 600 ex be able to handle a 14-28 T rear or am I doomed to finding a descent rear changer with a longer cage ? if this is the case what would you recommend that is both cheapish and readily available.

CO_Hoya 

If Velobase is to be believed (and no reason not to), the description indicates that a 28t rear cog is the largest it will shift. Going from 24t to 28t in the back will get you from 38" to 32.5" in gear-inches, about a 16% easier gear.

Your chain wrap would be 16t (front) + 14t (rear), 30t so only 2t beyond spec. That should be acceptable so long as you avoid cross-chaining (high-high and low-low). I'd say you should give it a try and report back.

non-fixie 

I concur. Try 14-28. 34 x 28 is my go-to L'Eroica gearing. And so far all my short cage Shimano RDs were able to handle that.

Daveyk15

Thanks for the advice I will order a new 14-28 block and give it a go.

davester

Also, err on the side of a slightly longer chain that will sag in the small-small combination rather than a shorter chain that will lock things up and cause irreparable damage when accidentally shifted into big-big.

old's'cool

FWIW I'm running the same RD with 36-48-52 triple and 13-28 rear cluster with no issues. Shifters are Ultegra SIS bar ends.

Daveyk15

Fitted the new 14-28T Shimano block and it works like a charm