Originally Posted by
Bill Kapaun
If you look at the recommended cassettes for that Gruppo and take the worst case scenario RE: chain wrap, the 16T (or other) is about all the wrap capacity you have left.
Add the fact that a 16T jump is getting pretty large. Any more than that starts to result in much crappier shifting.
not 100% current shimano rear derailers have a number of specs for ranges. Mininum read cog, Maximum Rear cog, Chain wrap and maximum front ring difference. It is entirely possible to be within the chain warp spec but out of front ring difference. Shimano seems pretty clear about no more that 16 front difference in that they don't sell current cransets with greater than 16 t difference.
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