I have a trek r200. The low gearing is not low enough. I've learned a whole new bunch of terms and have calculated gear-inches of 26.6, plus I have at present oversize tires on my 20 inch rims. I have a single chain ring of 40 teeth that runs to a 5 speed derail of 24 teeth largest cog that is on a fixed 24 tooth cog that drives the rear 8 speed derail (30-11). It seems the easiest way to get some lower gearing would be to change the fixed 24 tooth to a smaller cog size, but of course that would also change my high end. So then I'd need to change the 5 speed 24 to a larger cog size etc. So two questions:
How large a jump can a derailer accommodate between cogs. I've read 10 to up to 16 percent.
Next question that I know is not possible to get a definitive answer to, but what do other bent riders feel is a low enough gear ratio for touring. I manage to go up some fairly steep hills, but my knees are killing me and I guess that's not a good thing. I've read that a good cadence of 80 is better in the long run. Any thoughts out there...thanks