Is there an ideal tire-width-to-rim-width ratio?

[Blueblade]

I posted some pictures here where we were talking about frame Flex:

Oracle frame flex

Thanks for starting this, I was going to as well. The duro crux 3.25 tire on my new Oracle 27.5 (Jan 2022) rubs against the frame, but it doesn’t take super hard pedaling, merely mounting, or slightly more pressure due to feeling close to losing balance causes it. (I’m a beginner moving up from a club 24, before I’m really ready to). I am heavy, close to 240lbs/108kg, so that doesn’t help I am sure. UDC support suggested I check the bearing caps hadn’t loosened).. I tightened them some, whic…