Puzzled by how little it took for the gears for S Korea, I checked the 4 Rivers trail and it indeed seems mostly flat, but there is one peak in the middle. My biking experience with S Korea was very brief, just around Busan, but, in spite of somewhat built up gears by then, I had to resort to walking at places to reach elevated neighborhoods.
No breakdowns is pretty amazing. You must maintain your bikes well, but very limited luggage, not straining the bikes, presumably helped somewhat too. We are leaving onto some short tour tomorrow morning and there is presumably a lesson there we should use.
This is the peak in the middle of which you speak. It is only about 560m from memory. And it is a more gradual climb from the north, the direction from which I tackled it, than from the south.
47t x 11-36t ~ 26 gear-inches.
I was only carrying 4.6kg (plus a 2L of water and my 75kg frame at the time) around. No need for higher gearing on the three of the five Four River trails I did.
The highest mountain in the ROK is only 1,900masl. Taiwan peaks at nearly 4,000 and has over 250 peaks over 3,000m, making it not only high but densely high. It's by far the most mountainous place in East Asia and climbing can be quite daunting there. I was born in a country roughly the size of the ROK and which has 37 volcanos, one topping out at 4,200masl. On a clear day I can see a 3,100m peak here from my home in Bali. The landscapes of places like these, born in plate boundary locations and of plate collisions or volcanism are qualitatively different. That's Taiwan, that's Bali, that's my country of birth. The ROK's terrain is not of that exaggerated, daunting type. At least not along the Four Rivers paths.
.
Touring light has positive effects beyond weight:
- easier & quicker daily packing and unpacking
- Less strain on the bike & mechanical complication
- Better aerodynamics
- More agility and nimbleness when you ride into town.
.
I am puzzled by your surprise that I suffered no breakdowns. Road and surface conditions are far from bad, quite good actually, in the ROK, and my gear and equipment were solid.