Rear derailleur options for 1x11 di2 ?

[einreb]

Looking at running a 'budget' 1x11 di2 on a cross bike and slightly confused by the derailleur options. Any insight is appreciated.

I'm looking at what I *think* are the cheapest 'clutch' di2 optioons. t looks like the XT RD-M8050 runs a bit cheaper than the Ultegra RD-RX805.

Any reason not to run the XT? likely pair with Ultegra shifters, max of 34t in the back, any other considerations?

TIA,

-Bernie

[joevers]

Both those options are fine. XT and RX817 should take an 11-40 or 11-42, the RX805 should take an 11-34 and is part of the Ultegra series with a clutch. If you're only ever going to run an 11-34 the RX805 is what I'd do, it probably shifts a hair better than the other two mentioned and saves a few grams.

[RobJ]

Those are the ones for a 'budget' option. The GRX would be one but run more.

If you only want a 34t max then the Rx805 would be the one. It's low range is a min of a 28t with a 34t max.

The XT is a nice option, I ran it myself. Except the min rear is a 40t with a 46t max. Depending on your riding the 34t max might not be enough.


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[JWB475]

I have been running a 1x XTR Di2 with the small SW-R9150 climbing buttons mounted on the insides of my TRP Hylex RS brake levers. I also added another set on the inside of the drops so I can shift more easily when riding in the drops. But depending on your riding style a singe pair of the climbing buttons would work fine.

I didn't necessarily do this for budget reasons, but it may be a more inexpensive option. Plus the TRP Hylex RS brakes are great and the hoods are super comfortable. https://trpcycling.com/product/hylex-rs/

TRP also makes an adapter to run the bulkier SW-R600 climbing switch on inside of their Hylex RS levers. https://trpcycling.com/product/hylex-di2-adapter-kit/ I have also used this and the adapter is really well designed and works well when shifting from the hoods, anywhere else and it can be a little harder to reach.

Any reason why you are limiting yourself to a 34 tooth in the back?

I have mainly used the SRAM XD 10-42 cassette, as well the e13 9-39 and 9-46 cassettes.

[old fat man]

Originally Posted by JWB475

I have been running a 1x XTR Di2 with the small SW-R9150 climbing buttons mounted on the insides of my TRP Hylex RS brake levers. I also added another set on the inside of the drops so I can shift more easily when riding in the drops. But depending on your riding style a singe pair of the climbing buttons would work fine.

I didn't necessarily do this for budget reasons, but it may be a more inexpensive option. Plus the TRP Hylex RS brakes are great and the hoods are super comfortable. https://trpcycling.com/product/hylex-rs/

TRP also makes an adapter to run the bulkier SW-R600 climbing switch on inside of their Hylex RS levers. https://trpcycling.com/product/hylex-di2-adapter-kit/ I have also used this and the adapter is really well designed and works well when shifting from the hoods, anywhere else and it can be a little harder to reach.

Any reason why you are limiting yourself to a 34 tooth in the back?

I have mainly used the SRAM XD 10-42 cassette, as well the e13 9-39 and 9-46 cassettes.

Got pictures of the setup with 9150? I run the XT derailleur with the climber button in the right trp lever. Works great with 11-36 cassette and 11-46. I don't adjust anything when swapping the wheelsets.

I believe the clutch in the rx derailleur is a lot "softer" than the mtb versions. I've seen reports of more issues on the rougher terrain with the rx derailleurs as opposed to the xt and xtr. Supposedly the grx clutch fixes this as well.

[one60]

No issues running the RX805 clutched Di2 RD with a (ghast) SRAM 12-36T cassette on my gravel 1X

[TerryDi2]

You can use any Di2 rear derailleur you like. They will all work ;-).
(well, except 7970 because the connector is different)

However, if you ever decide to add a front derailleur then it must be from the same 'category'.

The two categories I'm talking about here are:

• MTB
• Road/GRX

So all derailleurs in a Di2 system must be either all MTB or all Road/GRX.
(and they must all be 10 speed or all 11 speed)

Since you're running a 1x system these limitations do not apply, but if you're thinking of perhaps adding a front derailleur in the future do keep in mind that the Di2 MTB front derailleurs cannot be installed on all road bike frames

[einreb]

Awesome. Thanks for all the comments. Its almost like hanging out in the bike shop and nerding out on components in person. I miss that

Couple things to note about my situation:
1. I'm running mechanical/canti brakes. I really like the idea of running dumb levers (cheaper if wrecked in cx) and then some combination of sprint/climbing shifters that I can get to with my thumbs. Any experience with that and pictures would be great. I think I'd need a different 'brains' junction box if not running actual shifters? Although, Ultegra di2 mech shifters are low $200's shopping around and would play well with winter CX gloves and cold fingers.

2. I really don't need more than 32-34 here for Chicago area cross courses and non-race rides. Prefer tighter spacing and can swap out front 42-46 on occasion if really needed. So that info about min 40t for the XT rear may rule that out.

Grazie,

Bernie

[TerryDi2]

Originally Posted by einreb

Awesome. Thanks for all the comments. Its almost like hanging out in the bike shop and nerding out on components in person. I miss that

Couple things to note about my situation:
1. I'm running mechanical/canti brakes. I really like the idea of running dumb levers (cheaper if wrecked in cx) and then some combination of sprint/climbing shifters that I can get to with my thumbs. Any experience with that and pictures would be great. I think I'd need a different 'brains' junction box if not running actual shifters?

You can use either of these:

• SM-EW90A (below the stem, 3 ports)
• EW-RS910 (handlebar drop / frame junction, 2 ports)
• SC-MT800 display (attaches to bars, 3 ports, with BluetoothLE/ANT. smart battery/mount BT-DN110 or BM-DN100 required)
• SC-M9051 display (same as above, but more expensive)

It doesn't really matter whether or not you're using regular shift levers or not.
The only thing is that you cannot use the SW-R610 sprint shifters. Those only plug into the sprint-shifter-only port on the (non-hydraulic) ST-6870, ST-9070, ST-R8050, ST-R9150 levers.

Di2 doesn't really care how it is connected or what is connected to what, as long as it is connected to each other

If you're looking for the cheapest levers, the older ST-6770, ST-6870 or ST-9070 will work too.

[joevers]

I believe the di2 shifters are actually cheaper than the mechanical counterparts. The expense is in the derailleurs and the etube everything. That said there are quite a few racers in portland that put di2 remote shifters on hydraulic brake levers. Maybe this came from when Shimano did not have a good di2 hydro option, maybe because they liked the position of the shifters where they put them, or maybe they just really liked the TRP levers. It can for sure be done but the Ultegra di2 shifters are really not that expensive anymore.

[JWB475]

Originally Posted by old fat man

Got pictures of the setup with 9150? I run the XT derailleur with the climber button in the right trp lever. Works great with 11-36 cassette and 11-46. I don't adjust anything when swapping the wheelsets.

I believe the clutch in the rx derailleur is a lot "softer" than the mtb versions. I've seen reports of more issues on the rougher terrain with the rx derailleurs as opposed to the xt and xtr. Supposedly the grx clutch fixes this as well.

Here is my current set up with the 9150 buttons, this option does require some some diy/hacking to make it work...

I recessed the 9150 buttons into the plastic plate on the inside of the TRP Levers (using my drill press and a dremel, it was easy to do), and then I punched a hole in the rubber hood for the button. I also used the dremel to remove some extra plastic from the buttons mounted in the drops (the tabs for zip ties), they are held in place with some double stick tape (and the bar tape). I also really love being able to hook my thumbs around the lower set of buttons on the drops.

This set up is duplicated on the right side. The right side buttons move the derailleur to the right, left side buttons moves it to the left. Using the e-tube software you can program them to do whatever you like, I believe you could also make them work with a FD using the software...

[one60]

JBW475's approach is really slick and well done. The Hylex / Di2 combination makes for a unique project (and cost effective). IIRC, there are some eTap versions out there too? Perhaps on Road.cc or BikeRadar but someone integrated nintendo buttons in the shifter body

Mine here...
https://forums.thepaceline.net/showthread.php?t=255861

[robt57]

Originally Posted by JWB475

Here is my current set up with the 9150 buttons, this option does require some some diy/hacking to make it work...

I thought the sprinters needed to plug into the 3rd port on ST-6870 or newer? What is your connectivity on that setup?

Thanks in Advance...

[TerryDi2]

Only SW-R610 , like I've said above

[JWB475]

Yep, the SW-R9150 and SW-R600 climbing switches can plug right into a junction box. so you don't need the Di2 compatible brifters for them to work

I used to have an external junction box, but now I am using a bar end junction.