Configuration
|
1
|
2
|
3
|
4
|
5
|
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Notes
|
Typical 3x9
mountain bike |
Typical 2x9
road bike |
Typical 2xX
folding bike^ |
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Tire Size
|
44-406 (20")
|
44-406 (20")
|
54-559 (26")
|
23-622 (700c)
|
35-406^ (20")
|
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Crankset
|
Rotor 3D
175mm
|
Dura-Ace
172.5mm
|
XT
175mm
|
Dura-Ace
172.5mm
|
~170mm
|
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Chainring
|
50*
|
34*
|
53*
|
40*
|
44*
|
33*
|
23*
|
53
|
39
|
55/44^
|
Cassette
|
11-34 (as)
|
11-34 (as)
|
11-34 (as)
|
12-27
|
11-32^
|
|||||
Gear-Inches
|
84.9
|
57.7
|
90.0
|
67.9
|
103.8
|
77.8
|
54.2
|
116.1
|
85.4
|
|
71.8
|
48.9
|
76.2
|
57.5
|
87.8
|
65.8
|
45.9
|
107.1
|
78.8
|
||
62.3
|
42.3
|
66.0
|
49.8
|
76.1
|
57.1
|
39.8
|
99.5
|
73.2
|
||
54.9
|
37.4
|
58.2
|
44.0
|
67.1
|
50.4
|
35.1
|
92.9
|
68.3
|
||
46.7
|
31.8
|
49.5
|
37.4
|
57.1
|
42.8
|
29.8
|
81.9
|
60.3
|
||
40.6
|
27.6
|
43.0
|
32.5
|
49.6
|
37.2
|
25.9
|
73.3
|
53.9
|
||
35.9
|
24.4
|
38.1
|
28.7
|
43.9
|
32.9
|
22.9
|
66.3
|
48.8
|
||
31.1
|
21.2
|
33.0
|
24.9
|
38.0
|
28.5
|
19.9
|
58.0
|
42.7
|
||
27.5
|
18.7
|
29.1
|
22.0
|
33.6
|
25.2
|
17.5
|
51.6
|
38.0
|
||
Min
|
18.7
|
22.0
|
17.5
|
38.0
|
~26.0^
|
|||||
Max
|
84.9
|
90.0
|
103.8
|
116.1
|
~93.0^
|
|||||
Max-Min
Difference
|
66.2
|
68.0
|
86.3
|
78.1
|
~67.0^
|
|||||
* - Rotor Q-Rings have a variable effect count during the pedal stroke, this is the nominal count
^ - Reference from Tern Verge P18 as of Feb 2014 (link) Peach indicates the top 1/3 range of gearings Green indicates the middle 1/3 range of gearings. Calculations done with the late Sheldon Brown's fantastic gear calculator (link) |
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Wow! What a table we have there. For the table, Now just to let you know why I put this up in the first place.
Basis for the Comparison
These four configurations are based upon my personal experience:
1. My current folding bike configuration
2. My previous folding bike configuration, as ridden in my Taiwan 2013 tour
3. My current mountain bike configuration
4. My previous road bike configuration (but I deliberately put in the 12-27 cassette to give more climbing gear ratios, however I believe I was using 12-25 previously)
5. A stereotypical configuration for a middle-range folding bike (Tern Verge P18)
These may or may not work for you, but configuration 3, 4 and 5 are likely to be good references for most mountain bikes, road bikes and folding bikes respectively.
Lessons Learnt
When I was doing my bicycle touring in Taiwan (link), I had ambitiously aimed to climb to the highest road in Taiwan which is known to be 3,275 meters in altitude, with my bike that weighed about 16 kg by itself, with another 18 kg of items in my panniers and rack-top bag. My weight would be about 65 kg, so that's a grand total of 99 kg of weight to be moved.
Here are the mistakes in my planning
1. I factored in only two days for the full ascent- I planned to reach halfway (1,600 meters altitude) by end of Day 1.
2. I did not have training nor experience in hypoxic (low oxygen) environments previously.
3. I did not have low enough a gearing to get me up with all that load.
What this means is that when I was trying to climb up the entire mountain (I bailed out at 1,100 meters elevation), I was using my ultimate lowest gearing at 22.0 gear-inches and had no more reserve gear to keep my legs from fatiguing fast! Worse yet, the next day when I restarted my ride... my legs were totally dead. I would have loved to have additional lower gearing then - but I guess I have to pay the price to learn thoroughly - always have at least one lower reserve gear to push!
According to EngineeringToolbox.com (link), the air density at 3,000 meters altitude is nominally at 0.9093 kg per cubic meter, while it's about 1.225 kg per cubic meter at sea level. That's some 34% lower amount of oxygen for each breath I take! This thinner air was what I was told about, but I foolishly thought it was easily accomplished without a hiccup.
However with the table I created above, I hope to show you though I cannot have the immense spread of minimum-maximum gear-ratios on my current folding bike setup (Rotor 3D 175mm cranks with 50/34 Q-Rings), I sure have the assurance that I have almost the same absolute low gearing on my folding bike (18.7 gear-inches) relative to my mountain bike (17.5 gear-inches), which is only 6.9% in difference. This sure beats my original folding bike setup with a lowest of 22.0 - and by looking at the table that means I'm running with two lesser lower gears compared to my mountain bike!
How this information will help myself with, would be to help remind me to pack less stuff on my bike so that it's easier for me to have a more favourable attempt to climb the mountain.
Basis for the Comparison
These four configurations are based upon my personal experience:
1. My current folding bike configuration
2. My previous folding bike configuration, as ridden in my Taiwan 2013 tour
3. My current mountain bike configuration
4. My previous road bike configuration (but I deliberately put in the 12-27 cassette to give more climbing gear ratios, however I believe I was using 12-25 previously)
5. A stereotypical configuration for a middle-range folding bike (Tern Verge P18)
These may or may not work for you, but configuration 3, 4 and 5 are likely to be good references for most mountain bikes, road bikes and folding bikes respectively.
Lessons Learnt
When I was doing my bicycle touring in Taiwan (link), I had ambitiously aimed to climb to the highest road in Taiwan which is known to be 3,275 meters in altitude, with my bike that weighed about 16 kg by itself, with another 18 kg of items in my panniers and rack-top bag. My weight would be about 65 kg, so that's a grand total of 99 kg of weight to be moved.
Here are the mistakes in my planning
1. I factored in only two days for the full ascent- I planned to reach halfway (1,600 meters altitude) by end of Day 1.
2. I did not have training nor experience in hypoxic (low oxygen) environments previously.
3. I did not have low enough a gearing to get me up with all that load.
What this means is that when I was trying to climb up the entire mountain (I bailed out at 1,100 meters elevation), I was using my ultimate lowest gearing at 22.0 gear-inches and had no more reserve gear to keep my legs from fatiguing fast! Worse yet, the next day when I restarted my ride... my legs were totally dead. I would have loved to have additional lower gearing then - but I guess I have to pay the price to learn thoroughly - always have at least one lower reserve gear to push!
According to EngineeringToolbox.com (link), the air density at 3,000 meters altitude is nominally at 0.9093 kg per cubic meter, while it's about 1.225 kg per cubic meter at sea level. That's some 34% lower amount of oxygen for each breath I take! This thinner air was what I was told about, but I foolishly thought it was easily accomplished without a hiccup.
However with the table I created above, I hope to show you though I cannot have the immense spread of minimum-maximum gear-ratios on my current folding bike setup (Rotor 3D 175mm cranks with 50/34 Q-Rings), I sure have the assurance that I have almost the same absolute low gearing on my folding bike (18.7 gear-inches) relative to my mountain bike (17.5 gear-inches), which is only 6.9% in difference. This sure beats my original folding bike setup with a lowest of 22.0 - and by looking at the table that means I'm running with two lesser lower gears compared to my mountain bike!
How this information will help myself with, would be to help remind me to pack less stuff on my bike so that it's easier for me to have a more favourable attempt to climb the mountain.
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