That's not accurate - the cage length determines the total amount of slack (chain wrap capacity) the derailleur can take up. If you used a short cage derailleur with a standard triple in the front, then that statement might be true, however, if you run a 2x9 or 1x9 setup it is not true. I use a SRAM X9 short cage derailleur with an 11x34 cassette. It's a 1x9, so there is a lot less slack that needs to be taken up.dabioman said:The cage length determines how large the largest cog can be. Short cage = 26 or so, Medium cage = 28 or so, long cage 34 or so. The b screw adjustment adjusts for the largest cog.