>>1398615Unpopular Opinion: You could easily ride a few more years on it because:
1) Its steel and its pretty compliant to that damage.
2) That area of the bike is naturally flexy and not as rigid as you think. Look at Moots titanium soft tails.
3) I had a crack in an aluminium specialised frame along that weld. Absolutely everybody said the frame would fail. Nope. I rode it daily for ANOTHER 10 YEARS until it failed up at the top of seatpost.
Inhibit the rust. Paint it. Ride it. Dont give a fuck. There is plenty of meat there.