36t to 34t 2x10, is 6-7% decrease in GI noticeable?
 

I'm setting up my bike for moderate touring and randonneuring, and I'm debating whether to swap the small chainring from a 36t to 34t. It will keep the 700x32 tires and 11-28 cassette. Looking at a calculator, that will be a change from 34.84 GI to 32.68 GI, or about 6-7% decrease.

Is this a noticeable and beneficial difference in the ability to climb? I'm not having too much trouble just riding around the city, but with 20 lbs of gear I worry that I will have issues on steep grades.

A few years ago I dropped my smallest chainring on the LHT I use for fully-loaded touring from a 26t to a 24t. I noticed the difference. I'd rather err on the side of having the lower end, especially since I have been incorporating more unpaved riding into my tours..

A small change, but I think you'd be unlikely to regret it. :thumb:

2 foot gear is always your back up..

52 : 36 was my recreational hill climbing gear

That difference is quite noticeable. Whether or not you need the lower gear depends on you. 36/28 could be ok for randonneuring if the hills aren't too big or you are a strong climber. Most randonneurs I know have even lower gears than 34/28. 34/34 or 34/36 is pretty common for people running a compact crankset. Plenty of people run 30T chainrings or even smaller if they have a triple.

You'll feel it but soon after you will want more. I did this in steps starting with 36T/28T (front/rear) then to 34T/28T and ended up with 34T/34T. Now I am thinking about 34T/36T due to wanting just a little bit more...

Find 2 gears on your current bike that are 6-7% different, and judge for yourself how different they are, while going uphill.

Yes, its a good change. I do some climbing in the black hills of SD and I put a 34t on when I am there and I am very pleased I do. Its not huge but you can sure feel the difference and its just more enjoyable with a little bit better gearing for hard climbs....this is my observation though.

FWIW I do put the 36 back on when not in a hilly area but that is most of the time anymore.

That's a smart idea, thanks. Will probably find that the consensus is correct and I should swap it to a 34t.

Thanks everyone!