Let's talk Gear Inches

snoogly

Maximum Pace
Oct 14, 2007
695
48
48
Machida, Tokyo
#1
I am in the process of working out the gearing ratio for the Rohloff internal-hub, 700c 'dirt road' bike I am endeavoring to gather parts for. It's a 14-speed IGH, to be used with a single cog at the front.

Based on the 16t sprocket on the hub, and a 42t cog at the front, I used the Sheldon Brown Calculator (http://www.sheldonbrown.com/gears/internal.html) to come up with a range of gears from:

104 gear inches

to

19.8 gear inches

(My MTB has a range of 103 to 17.7 gear inches.)

This is the calculator for normal gears: http://www.sheldonbrown.com/gears/index.html

The 104<>198.8 range I would get using a 42t cog is the closest I could get to the ratio on my MTB, but I was wondering what the gear ratios are (in gear inches) of the TCC stalwarts' road bikes.

I cover similar terrain to you (but at a considerably slower pace), and I am curious about how my Rohloff equipped bike will compare to the gearing ration of your road bikes.

My addled brain gets befuddled when thinking about gears, and 'gear inches' is the only way I can conceptualize it.
 

Philip

Speeding Up
Feb 15, 2007
765
7
38
Setagaya
#2
53 35.9 % 39
12 116.1 85.4
8.3 %
13 107.1 78.8
7.7 %
14 99.5 73.2
7.1 %
15 92.9 68.3
6.7 %
16 87.1 64.1
6.3 %
17 81.9 60.3
11.8 %
19 73.3 53.9
10.5 %
21 66.3 48.8
9.5 %
23 60.6 44.6
8.7 %
25 55.7 41.0

Cheers,

Philip
 

AlanW

Maximum Pace
Jan 30, 2007
1,214
435
103
Tokyo
#3
Lowest 33.1 to Highest 109.5 on my bike is a good range for me in Japan.
I use every gear except the crossovers 34/13 34/12 and 50/27, although my bike will of course run in those gears if needed.
 

Kaffekata

Warming-Up
Apr 27, 2008
51
0
0
Tokyo, Jpn
#4
To add to your database, my cyclo-tourer has a gear inch range of 25.3 to 127.6 (whatever that means). I almost never use the extreme gear ratios, but maybe I will after I put on the rear rack & trunk and do some serious touring.

My cog is 11 x 32 and my crank is 52x42x30. My tire size is 700x32. According to Sheldon Brown's calculator, my theoretical maximum speed on a straightaway is 42.6 km/hr. So far, I've only managed to hit 40 km/hr in short sprints.

Hope you find this info useful.
 

yokotas13

Warming-Up
Feb 15, 2008
70
0
0
33
Akirunoshi
#5
To add to your database, my cyclo-tourer has a gear inch range of 25.3 to 127.6 (whatever that means). I almost never use the extreme gear ratios, but maybe I will after I put on the rear rack & trunk and do some serious touring.

My cog is 11 x 32 and my crank is 52x42x30. My tire size is 700x32. According to Sheldon Brown's calculator, my theoretical maximum speed on a straightaway is 42.6 km/hr. So far, I've only managed to hit 40 km/hr in short sprints.

Hope you find this info useful.
My max with a 42/16 is 38KM/Hr
With my 46/16 its up to 40KM on a fixed gear and i can keep it up for maybe a KM?

I so need to get the S3X fixed internal hub