Gravel / Gravé / Gnarmac / Groad / ATB

Does KMC have a longer chain then? I've only seen 114 and 118 or whatever the standards are.

You paying for the powermeter and cranks to make that work?

that is a lot of swing

Even though we've not met you know me well.

I still don't fully understand capacity. It implies you're going to cross chain big-big and small-small, right? What if you just don't do that, and shift your chainring at the 'right' time? Then you can get away with a lot more (range)?

I guess the downside is you have shift your chainring at the right time, otherwise you're screwed.

Derailler capacity people are flat earthers. People who throw on an RD and just make groovy shit work are landing on the moon baby.

The earth is round, just like a cog.

Take me to your derailler

GRX mech with 11 sp 11-51 on Instagram

Shimano always conservative on mech range

Goat link a bit cheaper obvs

Yeah, I didn't want to change the mech. The one on here already cost £250.

Someone was explaining the GRX derailler to me recently. It has a different parallelogram swing or something so works better with wide range cassettes than road stuff. I mean, that's the point, but it's nice that it's actually true.

Yeah, I am running the GRX RD-RX810 on an 11-40 cassette although it's rated for a 11-34 (same for the RD7000).

That video is of a 1x setup though, you see how the chain tensioner goes from fully nested to fully deployed on that cassette? No room left for a 2x like @hippy "needs"

£250

A rear derailleur?
The GRX has a better clutch too compared with the Ultegra RX I think, that could help on your 324 links chain

What about the 11-42T RD?

Yeah, that's the price you pay in a shop. At least it was, 12 months ago.

Still £209 at Wiggle
https://www.wiggle.co.uk/shimano-ultegra-r8050-di2-rear-dearailleur

The RX810 might clear that, probably need a longer B screw than the stock

Ahh Di2, forgot you want to have all the frills

Been looking into this myself and somewhere on another forum I found loads of people running 11-46 on GRX 812 mech without issue.

Remember this is a road bike that is being moved over to gravel. I wasn't going to swap the shifters but they pissed me off enough that I decided to swap them along with the bars. The RD can wait until it gets fed into the back wheel. The cranks/PM can wait until they die.

Which one is the 812 one?

There's 11-32 and 11-42 versions but I don't know which is which.

You say want, I say need.

11-34: 810/815 (Di2)
11-42: 812/817 (Di2) Also looks really ugly

Ok, the 812 is the bigger cassette one.

https://bike.shimano.com/en-US/product/component/grx-11-speed/RD-RX812.html

Ah, yeah, even I forget I need the Di2 one. Looks are of no concern to me. It's a leccy gear changer, nothing more nothing less.

https://bike.shimano.com/en-US/product/component/grx-di2/RD-RX817.html

Actually, if I'm going to all this trouble, can I run an Alfine hub and DI2 off-road? No derailler to smash off, right?

It's basically an XTR 9050 one

Are they £4000 per derailler? I don't want anything with XT in front of the name of something that's definitely going to be crashed. I have a spare older style Ultegra RD I could maybe use with a Wolf Tooth. I wonder if that would get to 46T?