Hello everybody!

like many others the pandemic has got me back cycling! and I’m back into it in a big way.

im lucky enough to live near a great forest full of amazing bridal paths and gravel tracks so I choose a gravel bike as my new lockdown toy.
the bike I choose is the GT Grade Elite. And I’m really very happy with it!

however being the nerd I am. I’m already looking at future upgrades to the bike!

i would like to fit the Shimano 105 rs7020 groupset in the future as it seems to be a fantastic choice for the money and a massive upgrade over the existing Claris set up.
now this is where it gets slightly more confusing and my head scratching begins.
The GT grade elite comes with a 73mm BSA bottom bracket shell. From the reading I have been doing. This is a mountain bike size BB. and therefore the 105 which being a ‘road’ groupset. Will not fit?
so what are my options?

is there a bottom bracket available with narrower bearing cups that allow it to work?

Is facing my frame down to 68mm (or 70mm?) the only way? and if so. Could I take the difference off of just one side to avoid messing with the chain line?

should I scrap the idea all together and upgrade everything else to rs7000 bar the chainset?

thanks for reading and I’m sorry if there’s too many questions in one post. I didn’t want to spam the forum being brand new on here.

Rich