Originally Posted by Kapusta

I think the weight savings being quoted here are way too optomistic if comparing similar levels of components. Lets look at XT 2x10 and 1x11

You will gain weight in the cassettes:
---11-36 10sp ~330g
---11-46 11 sp ~439g
So you gain ~ 110g there

You will lose weight at the crank:
---FC-M7100-1 (32t, 175mm): 631g
---FC-M7100-2 (26-36t, 175mm): 674g
You lose 43g there

Things that go away:
---XT front der: 146g
---XT front shifter 122g
---Cable and housing: guessing ~70g
So you lose 338g of stuff

So this has you netting a ~271g weight loss. So this back-of-the-napkin estimate is around 0.6 lbs.

These weights are taken from a variety of sources that I have not completely vetted. If someone has better number to plug in here, have at.