Some just need to get their head out of their aZZ too. The paralleogram of the short and medium is the same, and that is what determines big cog capability. Cage length is about chain wrap. AFWIW dunce, I'm not the only one having done it.It's fairly common practice.hd reynolds said:Well that's just the problem with a 'know it all' - you think you know better than what the manufacturer intended it to be. Like I said, it MAY work but is not recommended - because it is not the optimal component for the intended use. It may result in miss shifts, shorter component life and alike. Misguided information just because you've done it does not mean you are right.