Partial Tiagra -> 105 conversion questions

hi everyone, did some research and think this will work, but wanted to ask outright to people with more experience than I.

I am currently running full Tiagra on my road bike, and am considering upgrading from 10sp to 11sp so that I don’t have to change cassettes when I swap rear wheels between my roadie and my 11sp tri bike.

If I’m understanding it correctly, I should only need to change the chain, cassette, rear derailleur, and rear shifter, is that correct?

In other words, am I fine to keep running my existing Tiagra crank, front derailleur, front shifter, and brakes? Thanks all.

I believe that is correct. Shifter pull has changed 10->11sp, and derailleur ratio as well, so you can’t mix 10 and 11 on the shifter or derailleur side. I’m just not 100% certain about the font derailleur pull ratio, I assume it’s fine but can check. Did you verify the brake pull as well?

Yes. You will be fine doing this.

i think you don’t have to change the RD IIRC. Also check if your freehub body is 11 speed compatible

edit: if you are running 4700 tiagra