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Discussion Starter · #1 ·
New build is going to be a do it all kind of bike. Fitness, long rides, bike packing, dirt/gravel. Originally, I was just going to put an Ultegra 6800 RD on it and go with an 11/32 cassette. But I started thinking, what if I'm loaded up with gear and in the mountains? Having a lower gear would surely be nice.
Here's my dilemma: get the Ultegra, and later on buy the XTR derailleur, 40t low gear cassette, and a second chain, or just get the XTR and use it for everything. It'll be 95% regular road rides. Yes, I'd get a new chain and cassette when I need to go touring.
Thoughts?
 

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'brifter' is f'ing stupid
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New build is going to be a do it all kind of bike. Fitness, long rides, bike packing, dirt/gravel. Originally, I was just going to put an Ultegra 6800 RD on it and go with an 11/32 cassette. But I started thinking, what if I'm loaded up with gear and in the mountains? Having a lower gear would surely be nice.
Here's my dilemma: get the Ultegra, and later on buy the XTR derailleur, 40t low gear cassette, and a second chain, or just get the XTR and use it for everything. It'll be 95% regular road rides. Yes, I'd get a new chain and cassette when I need to go touring.
Thoughts?
Won't work. Any derailleur that is compatible w/ a 40 cog isn't compatible w/ road shifters.
 

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I love to climb!
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Won't work. Any derailleur that is compatible w/ a 40 cog isn't compatible w/ road shifters.

Might a better solution be to leave the rear gears as-is and change the crankset to something like an FSA Afterburner 28-40T? Would the necessary change in the front derailleur be compatible with road shifters or is the pull ratio different on that too?
 

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I think you will be OK with the front shifter pull ratios (please confirm), but if you go with a smaller ring on the front, you may not be able to get the derailleur low enough to match the ring diameter. This would be more likely with a braze-on, vs a clamp style, but it's still something you'll want to check before you invest in the new components.


FWIW I used Ultegra 6800 shifters with a XT M8000 Shadow RD and a 11-42 cassette using the WolfTooth TanPan solution mentioned above.

It's less than ideal, but it works.

Be sure to read up online (including the threads here on RBR) about this to see what the challenges are. Rear MTB derailleurs have a different cable actuation angle than road derailleurs, and if you are using internal cable routing, depending on where the RD cable exits the frame, you may not be able to put the TanPan on the RD itself, which means an inline solution hanging under your handlebars (youll need the inline adapter for this). Also, you'll probably need the Wolftooth Goatlink/Goatlink 11 to change the RD position.

Again, this is not ideal. If you love the way your bike shifts now, you might not love it so much with this setup. It's just not going to be as clean and quick shifting (at least it wasn't for me). That said, it works, and I use it, at least for now.
 

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The pull ratio on the FD and RD was changed when Shimano went from 6700 10spd to 6800 11spd. The FD was a clean sheet design and wont work well with anything other than the 6800 shifters.

Now as said, the XTR wont work correctly with the road shifters. The only brand that does work is SRAM, their road shifters can pull their MTB RD as they use the same ratio from road to MTB. There are some other quirks, but that is the just of it from what I researched.

Other option is Di2. You can use the road shifters and a XTR Di2 RD, little pricey but works very well.
 

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It'll be 95% regular road rides.
Thoughts?
I would build it for your 95% case, and use the 6800 RD.
With a 34 front/40 rear, at a cadence of 80, you'll be doing about 5 MPH. This is walking speed. Which is always an option to get over the steepest slopes, given the right touring shoes.

Unless pride takes that option off the table.
 

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I would build it for your 95% case, and use the 6800 RD.
With a 34 front/40 rear, at a cadence of 80, you'll be doing about 5 MPH. This is walking speed. Which is always an option to get over the steepest slopes, given the right touring shoes.

Unless pride takes that option off the table.


40 rear? No way a 6800 RD can handle that. It is only specced to 32T.
 

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'brifter' is f'ing stupid
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I would build it for your 95% case, and use the 6800 RD.
With a 34 front/40 rear, at a cadence of 80, you'll be doing about 5 MPH. This is walking speed. Which is always an option to get over the steepest slopes, given the right touring shoes.

Unless pride takes that option off the table.

Or derailleur spec.
 

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Discussion Starter · #12 ·
I've walked my bike up a few ultra-steep climbs while on the way to Golden Gate Canyon State Park. Hey, I live in the Houston, Texas area! There's no shame in it for me. However, I'm thinking if I'm bike packing with a bit of gear, I might need some extra help on those steep climbs. Since I already have the shifters, I'm thinking I might just try to HTFU, or use my MTB if I know I'll be where I need the gearing.
 

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40 rear? No way a 6800 RD can handle that. It is only specced to 32T.
Fully get that. My point was go with the 6800/ 32 to cover the 95% case, and if need be, walk the bike for the small number of times, some small percentage of the of the other 5% you *might* need it.
On getting the 40T XT rear to work with road bars - probably bar end shifters in friction mode would be the only solution.
 

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The last solution I would point out - use the new Shimano Tiagra 4700 components, albeit 10 speed. It's the only decent Shimano road groupset left that offers a triple crankset - 50/39/30. And with the largest rear cassette / derailleur cog supported being 34T, you get a fairly low 30 front, 34 rear combo for the steep.

I have a set of 4700 Tiagra shifters here, and I have to tell you, they are identical in hood shape and appearance to the 5800/6800 shifters. The old 4600 side exit cable and gear indicator window are *gone*. They use "under the bar tape" cabling for brake and shift cables. I would not be surprised if they were essentially 5800 shifters but with 10 speed internal parts instead of 11.
If you really want a "do it all" road/touring/gravel bike with lowest possible gearing, this would be a decent solution.
 
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