The negative consequences is 1x to 2x shifters

[d_douglas]

Most of my riding is commuting on my 1x10 CX bike.

I went out for a leisurely ride tonight on my Speedvagen with Record 2x11.

So used to not shifting on the front, I was riding in the 52t and just kept upshifting to the biggest cog until ‘kapow!!’ - the derailleur binds and goes Into the spokes! Until now, I’ve never crosschained a bike to the point of causing damage.

I released the rear wheel and loosened the chain, but it turns out I sheared off a few teeth of the lower derailleur pulley. I am not sure if I damaged the derailleur itself or the frame, but don’t think so (other than a nasty scar on the chainstay from the chain binding).

At least I didn’t get hurt and I was only a few km away from my car - I walked it back and just called it a night - I didn’t even break a sweat.

All this to say that I think 1x gearing deprograms you from making the best gearing choices and clearly 52-27 was a bad one ;)

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[lawgrad12]

This strikes me as a L limit screw issue rather than a gear selection issue. You should be able to cross-chain all day. Sure, it may be less efficient and cause increase wear and tear, but it shouldn't be tossing your derailleur into your spokes.

[d_douglas]

Yes, agreed. It shouldn’t have done that. Something was amiss.

[dddd]

You'll probably want to check the frame's hanger alignment, and then check the derailer for it's perfect straightness when you reinstall it.

I usually check rear derailers by holding them up so my eye is perfectly in plane with the flat end of the mounting bolt, then glance at the cage/pulleys to see that all is parallel with the end of the mounting bolt.
A further check is then to check that the cage of the mounted derailer is parallel with the larger cogs (which must be somewhat clean to see) with the cage in both a vertical and horizontal orientation.

[Ralph]

Agree with above....sounds like adjustment issue to me. I use big to big all the time on 2X....if that is gear I need. While not ideal.....if I want one gear lower, without dropping down in front.....I use it. If I'm in a pack on a short climb.....sometimes have to do that. The world won't end if you occasionally do this.

[unterhausen]

I use the big-big +1 method of sizing a chain, which means you can ride in that gear. Now that I changed to a 46 tooth big chain ring I ride in that gear occasionally. It's still bad though.

[Dave]

Changing to a smaller big ring does not require a shorter chain. If sized correctly, using the little/little method, you will get a chain length that maximizes wrap capacity.