Originally Posted by
ridethecliche
OP seems to talk a lot about how he can't afford a reliable power meter but seems to come up with lots of dough for all sorts of useless things.
I just pulled the parts from my spare caad9 - all I had to buy so far was a seat post.
As for the 27t cog.. I don't know for sure what the average speeds for this hill will be, but if I can have just 1 extra gear then it will help me to have fresher legs than if I mashed up at a lower cadence.
for reference, here are some common gearing options... lets use an example of 11 mph going up that hill in the 39t ring, the easiest gear for each cassette would give this rpm:
11-12-13-14-15-16-17-19-21-
23T (11-23) 81 rpms
12-13-14-15-16-17-19-21-23-
25T (12-25) 88 rpms
12-13-14-15-16-17-19-21-24-
27T (12-27) 95 rpms.