Originally Posted by thirdin77

Well, to follow up and so that others can use this thread as a reference, I did replace the 110mm bottom bracket with a 113 and now it'll shift into the small ring.

With the 110mm bb, I had tried adjusting the cable tension and the front derailleur rotation, both to no avail.

While inspecting the set-up as as whole, though, noted that my low stop screw was almost all the way out and that letting it out any more would let the derailleur hit the seat tube. As well, my high stop screw was almost all the way in.

Given the above, it seemed obvious that the crankset was situated too far inboard so it needed to come farther outboard- but how far? To find out, I loosened my high stop screw all the way and noted that there was about 3-3.5mm clearance between the chain and the outer cage fo the front derailleur so that was how much wider my bb could be while still being compatible with my Tiagra front derailleur.

That being, I chose to upsize by a small increment, from a 110 to 113, understanding that I could get 1.5mm more width on the drive side.

After installing the 113, I can adjust the front derailleur's low stop such that the chain doesn't rub when I'm in my small ring/big cog combination and there's still enough clearance between my front der and my seat tube.

On my test ride, shifting was mostly fine except the chain would sometimes kink- like it was being folded into an s-shape- when I shifted from my small to my middle ring so that's the next fun problem to work with.

Coincidentally, my Park chain checker says my chain is stretched to .75", though it's a nearly-new HG73 chain. Also, I did exceed my front derailleur's manufacturer-stated capacity of 20T as I'm running a 22T capacity. So I guess I can reduce the capacity/small ring or change the chain if troubleshooting and tuning fails.