Wow, this is creepy. AeroKroil is exactly what I sprayed on my stuck sprocket yesterday and let sit overnight (before seeing this post today). I’ve been hooked on this stuff for 40yrs now since using it at work on rusted cross-arm and transformer bolts. Today I gave the rear wheel a few more jerks back and forth and the sprocket popped off in my hand. No puller needed. Slapped the 16 tooth on there, buttoned everything up and went for a ride. Ahhh !!! This is the bike I had hoped for almost a year ago when I bought it. What a difference 500 rpm makes as well as all the new shift points. I absolutely love it. Before today for a year now every time I rode this bike I’d try and pull 6th gear. Not now. Rode 50 miles this afternoon and never tried for 6th even once. 5th gear now truly feels like overdrive. Thanks for everyone’s advice and help with this upgrade. Happy riding !!!