seing 9 and 10th tooth cogs mentioned, heres a question for all of you. I find that on both my bikes that have 11 cogs, I dont use the 11s that often and a big part of that is because whenever Im in them, it feels "crunchy" slightly. Ive always assumed its because of the tightness of the chain over so few cogs. I mean I use it when I have to, moreso on the mtn bike with the 42/32/22 on downhills as I get into the 42/11 fairly quickly, but I generally avoid it in going up to the next chainring when I can (never go into it in the granny)
Do others feel the same? I dont know if its my rd setup that does this, or if in fact it is the chain being on such a small diameter cog with so few teeth. Just as cross chaining can produce a sound from a chain that seems to say that it is being worked harder, it seems to me that on a 11t it does also, and I assume a 10 or 9t even more? I guess being in it for short periods is never going to be an issue, but I do know that some riders may go onto it often, and I wonder if it shortens the life of a chain?
As said above, 9 and 10 speed cassettes are different from the cogs on them. That said, I suspect that the 'crunchiness' you feel may be a misalignment of the derailer in the high gear. The limit screw may not be set properly or the cable may be tight so that the chain grinds a little on the cog while pedaling. You could also be hitting something...rack or fender screw...when in high gear. Check both.