I run a 28 miche rear cog backed up to a standard 12-25 shimano cassette using a short cage rear d & 39-53 front. This setup works but is at it's very limit. If i decide to go with a larger cog i will have to go with a long cage. With a triple you will need a long cage. The Dura-ace 9 speed GS uses what they call a smart cage. Its more like a medium cage but good luck finding one.