DubT

I just upgraded our Calfee 1 X 10 E-Tandem to SRAM etap 1 X 11. The current rear wheel freehub was compatible with both 10 and 11 speed cassettes. I did not want to have to upgrade to 12 speed AXS. I contacted SRAM and they still offer an 11 speed RED rear derailleur that with the use of AXS shifters or the AXS Blip Box will function properly. I have the RED 11 speed rear derailleur, the AXS Blip Box and Blip Buttons. The system works great!

Artmo 

Dub, do you find that 1X gives very large differences in gears, vs 2x?

DubT

I have been running 1 X for the past 6 years. 52 and 11-28. We live in the flatlands of Illinois. With the Mid drive BBSHD motor and a throttle we have not had any problem with the wind or any hill even big hills in North Carolina. The new 11 speed is 11-32.

Gravelmark

We went with SRAM eTap 1x12 this year and love it. So much easier to ride and the gear indication on the Garmin is icing on the cake!

DubT

What did you do about your freehub? Were you able to use a Shimano 12 speed cassette on the 11 speed freehub?

bwebel

Shimano 12 speed road cassettes fit the same freehub as their 11 speed cassettes. Most SRAM do not, though they just came out will a couple of ones that do. SRAM insisted on 10t cogs for their 12 speed, which you can't put on the freehub body size that have been in use for the last 30-odd years. (they also insisted on an incompatible chain; kind of ironic given SRAM's history of copying Shimano, who periodically tried to create incompatibilities so SRAM couldn't do so)

I've never use SRAM 12 speed shifting with a Shimano 12 cassette, but most things I've seen indicate that they are pretty much interchangeable. SRAM's shifting worked pretty well on the Rotor 12 speed cassette when I used it.

DubT

What cassette and chain are you using?

Chris_W

Our GRX Di2 front derailleur works perfectly and we have a massive gear range and decent gaps between the gears. I can't imagine what would be the advantage or point of getting rid of a chainring on any of my bikes, and definitely not the tandem. The MTB Di2 display is also great on the tandem to show the pilot the gear combo and battery level. 1x would result in unnecessary compromises and losses IMO.

reburns

I had to laugh when I read this because I feel exactly the same about all my old bikes with mechanically operated triples, including two tandems equipped with the now obsolete Shimano Flight Deck display.

DubT

My situation is unique in that our bike has an electric mid drive motor. We live in Illinois on the prairie so a triple and wide range gears are not necessary. For a few years I have used a 52 tooth chainring and an 11-28 cassette with “0” issues. If I need more power all I have to do is engage the throttle. I have 9 levels of assist and have 1500 watts of power if needed.

! X works great for us!

Chris_W

That would be classified as a motorbike in most countries. Completely different situation and gearing requirements.

TobyGadd

In his defense, he did start the post with, "My situation is unique in that our bike has an electric mid drive motor." Since many other people in this forum have e-tandems, his information might be beneficial to some.

DubT

That would be fine with me. If I had to put a license on it I would do it. We just returned from a very windy ride that we would not have done without the motor.

We do still have to pedal it for the PAS to function.

JSNYC

WOW. That is the first time I have heard of AXS shifters working on 11 speed etap. Did you have to do any custom programming for it?

I have an etap 11 speed kit on another bike that I could repurpose to the tandem, but that means new wheels, cranks, etc etc...which is a possible winter project...

DubT

I am using this rear derailleur: https://www.amazon.com/gp/product/B0...TF8&th=1&psc=1

I am also using the newest AXS Blip box. I had to do a firmware update on the blip box for it to communicate writhe the derailleur.