Joe B-Z wrote:
> I tend to use TA Cyclotourist rings with a tiny 24 or 22 ring.
The smallest ring made by TA for the Cyclotourist is 26 as far as I know. To go beyond that limit, I once made an adapter to use (steel) freewheel cogs as granny gears, with TA middle and outer rings - I used as low as 18 teeth. This was before the Mountain Tamer and other commercially-available versions were around. The adapter attached to the crank (to the, what is it? 49mm diameter bolt circle?) not to the other chainrings. Joe, do you use some sort of aftermarket adapter to get your low gears?
I saw one big problem with it: very high chain tension due to the extreme leverage ratio. This caused fast wear on the rings (aggravated by their small size - just fewer teeth to share the wear) and fast wear on the chain. Also increased incidence of chain breakage, which of course should ideally be near zero. I broke a couple freewheels too - the "guts" (pawls shattered).
Because of those problems I eventually took the adapter off and went back to stock chainring sizes, with suitably larger rear cogs.
Mark Bulgier
Seattle WA USA