Originally Posted by
billmagee
You guys amaze me. On steeper stuff my cadence drops to 60 or below and I have to tack back and forth across the road like a puffing sailboat just to make it to the top. I don't know what my HR is but it is pounding away in there.
My low gear has a gain ratio of 1.3. Any sense going lower?
Ok, if I understand gain ratio correctly, and you have a normal crank and rear wheel, your ratio of wheel radius to crank length is around 2 (340/170=2).
GR = lever arm ratio * gear tooth ratio = (wheel radius/crank length) * (chainwheel teeth/cog teeth) as I read Sheldon's paper on this.
To have a gain ratio of 1.3, your ratio of crank teeth to cog teeth must be around 0.65. If you have a 32 tooth largest cog in the rear, your smallest chainwheel must be about 20 teeth.
Is this a decent description of your low gear?
If so, it will be real hard to go lower. I've seen '70s era freewheels with a 38 tooth rear cog, but you have to be very well-schooled in C&V bikes and component selection to make this work.
You might really be at the limits of low-end gearing.
If I'm right, your only choice is to get stronger.