Originally Posted by
Clipped_in
I'm a 49 year old avid roadie toying with the idea of building up a touring bike to do some light-medium road touring. I am 6'-3" and weigh 190#, live in Utah (mountains), ride ~7k miles per year and would be considered a fairly strong recreational rider. I want to go with 10x2 drivetrain gearing with an 12x36 cassette, and I anticipate mostly weekend tours with an occasional 7-14 day biggie trip. I'll primarily be riding on pavement, but with potential for some gravel road / light offroad (ya never know if you decide to wander and explore).
What size chainrings would you suggest?
If you're going off-road or gravel road, then you will need to make an emphasis on lower gears because unlike riding on smooth pavement, gravel and rough roads provide more resistance. You will go slower for the same effort.
For a 2x10 drive train and if you are staying with Shimano, I would highly recommend using a Sugino triple crankset and make it a double crankset. 110/74 BCD is more versatile than a pure 110BCD compact crankset and the lowest 34T on a 50/34T compact crank on a 36 gives you a low 25". Low enough for light road touring, but not low enough on off-road touring especially dealing with loose gravel road until you hit an incline where you WISH you need lower gear. That's where a 110/74BCD Sugino crank comes in. You can mount a 26 or 24T and with a 36 on the rear, your lowest gear will be around 19 or 18" respectively. Low enough to climb a wall. For the middle chain ring, you can get by with a 42T or a 40T and to shift with that, you will need a Tiagra double front derailleur as this baby can shift with a wide throw more than 10 tooth difference no problem. By the way, I do have this setup currently on my touring bike with superb shifting and low gears to climb any steep hills we have here in the Rockies no problem.
As someone had said earlier. Road bike riding and loaded touring with off-roading intentions are 2 different things. Which is why I have a carbon road bike for hotel/motel/B&B road touring with a 30" low gear which is considerably higher than my all purpose touring bike. But I go heck a lot faster on it because it's heck a lot lighter and have bigger gears.
Hope this helps.