Originally Posted by
Fullcount
Let me verify that I am doing my gear inch Calc correctly. I am running 700c x 28 tires but using 27" in my calculation. (30/32=.9375) x 27= 25.3125 gear inches.
My wife's Jamis MTB is at 16.8". The suggested set ups only take me to 21" range. Since I am 220 lbs, I find getting up hills with a load a challenge. What should I target for hill climbing? Sub 20" range? Of course, loosing some of that 220 will also help, but I would like to enjoy some pedaling uphill vs pushing my bike.
Thanks for for all the help gang.
My three touring bikes run 19.3, 20.1 and 20.7 gear inches for my lowest gear.
The slowest I can maintain an upright balance without falling over is 3.5 mph. These gear ratios give me a cadence of roughly 60 at my slowest speed.
A lower gear would not help me balance any better, I still need at least 3.5 mph to stay upright, but a lower gear would increase my cadence. In anticipation of a big trip I may do, I have bought the hardware to set up one of my bikes with a 16.5 gear inch low gear to increase my climbing cadence. But I recognize that it will not make my load lighter, I still need to generate a lot of watts to get up a steep hill at the minimum speed I need to stay upright.
Not gearing related, just a comment - a 28mm tire is pretty narrow for your weight if you are also carrying a load of camping gear on your bike. But if you want to stay with a 28mm, you should probably use 26.6 inch wheel diameter for your calculations.
I still think you should just see if a 24t granny chainring will give you the gearing you want, and maybe a chain catcher. If that does not do it for you, then open up the wallet for lower gearing.