36t to 34t 2x10, is 6-7% decrease in GI noticeable?
04-08-19 | 10:45 AM
#1
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Joined: Sep 2013
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From: Upstate NY
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.
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.
04-08-19 | 10:53 AM
#2
Senior Member
Joined: Jan 2010
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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..
04-08-19 | 10:55 AM
#3
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From: CID
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
A small change, but I think you'd be unlikely to regret it. 
04-08-19 | 11:17 AM
#5
Jedi Master
Joined: Sep 2014
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From: Lake Forest, IL
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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.
04-08-19 | 12:34 PM
#6
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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...
04-08-19 | 03:23 PM
#7
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From: Ffld Cnty Connecticut
Bikes: Old Steelies I made, Old Cannondales
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.
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.
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Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
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04-09-19 | 05:45 PM
#8
Heft On Wheels
Joined: Nov 2014
Posts: 3,123
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From: South Dakota
Bikes: Specialized,Cannondale,Argon 18
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.
FWIW I do put the 36 back on when not in a hilly area but that is most of the time anymore.
04-10-19 | 09:07 AM
#9
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From: Upstate NY
