Originally Posted by
SoSmellyAir
What front derailleur ("FD") do you have? Does it have a trim function?
Shimano 2x10 and 2x11 drivetrains are designed such that, generally, one can reasonably use (a) the big chain ring with all or almost all of the cogs in the cassette, and (b) the small chain ring with the bigger half of the cassette plus at most 2 more cogs. Shimano dealer manuals expressly warn about chain rub and noise (presumably from the FD cage) when riding on the small chain ring and the smallest 3 or 4 cogs.
Are your 48/32 chain rings on a Praxis crank? Just spit balling here, but when you "converted to" these chain rings, you may have inadvertently moved the front chain line outward, which would be consistent with the chain lines you observed above while cross-chaining.
Shimano 2x10 and 2x11 FD can take four positions (from outermost to innermost): Top, T-trim, Low, L-trim. The Low position is for small chain ring cross-chaining, and is affected by the cable tension. However, based on what I outlined above, I don't think it is possible to eliminate chain rubbing on FD cage when cross-chaining on or near the small-small combination.
I agree with
Eric F that a single 32T chain ring would be too limiting on the "extremely long and steep hills where [you] live." It may work for climbing those hills, but you got to come down at some point, right?
It does have a trim feature. It’s a Shimano 105 FD. Based on what you have EricF have said, I will skip this whole drop the FD idea and adjust it better. I’ve had to replace the FD because something broke so I purchased a replacement Shimano
105 5700 (still being delivered). I’m told the broken FD might have been a 5600. So maybe the new one will operate so smoother. The praxis is a crankset
https://praxiscycles.com/product/zayante-carbon-s/ — 165. I think you’re right in how it probably modified the chainline.
With my bicycle I also put on butterfly bars and I’m using Microshift Thumb Shifters made for 2x10 road. I use the FD in friction mode, the RD in index mode.