Chain Deflection

[Marshdrifter]

I just moved from a 2 chainring/7 gear cassette combination to a 3 chainring/9 gear cassette and I'm curious about chain deflection. Previously, I just kept it off the first cog if in the big ring and off the 7th cog when on the small ring.

Are there any general guidelines I should follow?

 

[daveornee]

Originally posted by Marshdrifter
I just moved from a 2 chainring/7 gear cassette combination to a 3 chainring/9 gear cassette and I'm curious about chain deflection. Previously, I just kept it off the first cog if in the big ring and off the 7th cog when on the small ring.

Are there any general guidelines I should follow?

At least follow the same guideline you did before.
Now that you have more choices, you should know what they mean in terms of mathematics.
I suggest you take a look at the "Gear Calulator" on Sheldon Brown's site at URL:
http://www.sheldonbrown.com/gearing/index.html
There are other great articles on the general subject there.
I am sure that you will discover that you have nearly equal ratios from different front/rear combinations.
One general principle that applies: the straighter the chain runs the more efficient it is and the less wear there is on the drive train.
David Ornee, Western Springs, IL