The RX600, 46 tooth outer chainrings. They look the same (apart from one has ‘10’ printed on it, the other ‘11’). Is there a physical difference? Can I use the 10 speed on my 11 speed setup? (Can’t find 11-speed in stock, but there’s plenty of 10.)

I think the 10 speed only comes as 2x so will have shaped teeth on the chainring to help with front shifting. The 11 speed comes in both 1x and 2x. I honestly think you’ll be fine.

https://www.velonews.com/gear/technical-faq-10-11-speed-drivetrain-component-compatibility/

I was looking to replace the 11t sprocket on my 105 11 speed cassette but couldn’t find one in stock. I bought an 11 speed XTR one instead and it fitted fine and works great. It’s a bit confusing on the compatibility between road and mountain bike, and 10 speed and 11 speed.

@didnthurt Yeah, it’s 2x so no problem with the tooth shaping on those 1x chainrings. I’m going to order one and see what happens, I think.