Proper gear spacing
 

Is there a formula for the "ideal" gearing on a touring bike? Specifically, supported or light, road touring. I have studied Sheldon Browns gear calculator understand the % changes. But, is there ideal? My casette is 11-36, and crank is 52-39-30. But, I wonder if a 26 is in order instead of the 30, as my lowest gear inches is 22.5. I have 2 gears that are duplicated in this setup. Is that acceptable? There really are no hills here on the praries so I have nothing to experiment on. Just want to be ready for climbing the Rockies, and other North American mountains. Thanks

There can't be an "ideal," or even a recommended range. There are just too many variables, the most notable being the rider, but also including the amount and degree of wind and hills, the weight being carried, and budget or current equipment restraints. Frankly the main roads on the Rockies are not all that challenging - they are long but not steep, as many are limited in grade due to them being the only way trucks can get over the mountains. Most are in the 5-6% range. I found that a 5 mile climb was not much different than a 1 mile one, given that I was well fed and rested. Smaller ranges in areas where there are more roads are often more challenging - even a "short" 1 mile long climb at 8-10% grade can be a chore, depending on your fitness. My feeling is that if you have at least 8 cogs in the back you have enough gear selection that you are not going to gain a huge amount by going to a tighter cassette, and you won't have the dilemma of being out on the road with no bailout gear.


There is nothing terrible about duplicated gear ratios. For one thing with 21-30 different combos, that's a likely occurrence. Secondly, some of those duplicate combos do not have a good chainline. Thirdly, sometimes it's nice to have a ratio on uses commonly available on two different chainwheels. Finally, one has so many more ratios to choose from, spaced more closely than in the past that I think it's a non-issue.

You want "some" overlap between the rings.
Else, you get into that "sour spot" of having to double shift back and forth on slightly varying terrain/wind.

IF you are living in the flat lands, you certainly don't need a 30+ cog in back.

He's preparing for quite a different scenario.

With todays 8 to 12 cog cassetts, gearing is not really much of a problem. In answer to your question, IMO a granny 26 or 28 might be a good idea. It is apparent that you have checked gearing charts and know how to use them which is great. Try a few different chain ring combos with available rear clusters to get what you want with the fewist number of the same gear inches.

The bottom line here IMO is that with a large number of cogs on a cluster gearing is not a big worry. In my case my LWB bent has a 9 cog cassette. That makes it almost as good as pre 80s 10 speeds and all their half step shifting. Personally I mainly run on the center chain ring. I use my granny for steep hills, and the large chain ring for cruising with the wind or down hill. I do not sweat what gear Im in. I pick what ever gear feels right. I know that that kind of thinking gives "real cyclist" distress in the lower tract, but it work for me. :)

a Rohloff hub works for Me ..

When?
My guess, considering the time of the year, it'll be months away.
Why suffer "inappropriate" gearing in the meantime?

True, I did not consider that, but I don't see that he needs to suffer. Adjust out the granny chainwheel at zero cost, or he could certainly go for a closer ratio cassette for now and restore the other one when he's ready to tour.

Everyone has his own concept of ideal gearing. Mine is to have close steps in the ratios I use most of the time on flat ground or slight grades, then about 2-3 gears above that for descents and tailwinds (or when I'm feeling my oats), and then a series of steps to a low gear suitable for whatever I expect plus 1 step for bad days.

This is experienced based, so if I find I'm using my low routinely on climbs, I'll try to add one more at that end. Likewise if I find I very rarely use my highest gear, I'll eliminate it in favor of something at the low or mid range.

Since I use the upper half of the mid range mostly, I'm not at all a fan of 39/53 or current compact gearing since the large step is dead centerof the range, meaning I'll be spending too much time riding crossed over to get those middle ratios. Most of my bikes are set up with a 7 or 8 tooth difference in outer chainrings (and a bailout granny on the triple), matched with a cassette so that the chainring spacing is about 1-1/2 steps on the cassette. This arangement spreads the useage nicely among various combinations, and avoids the need for crossed chainlines.