[mhopton]

We're working with Alex @ mtbtandems.com on spec'ing out a new ECDM and have had some thoughts and discussions on whether 1x11 has enough durability and range for tandem use. We're a 295lb team that started out on our Fundango with 3x9 and now 2x10, which we've had ok success. On our 2x10 we're running 24/36 up front and a 12-40 rear cassette. I really need to spend some time with a gear inch calculator. My single bikes are all SS, so I'm a little out of the loop on the latest geared grouppo tech. However, my last geared bike was 1x11 and I really liked the setup.

I'm also interested in shimano's new XT m8000 group; supposedly they've made some big strides in shifter feel over the prior versions. With the long cable run on a tandem, shift lever effort always seems to degrade quickly and become increasingly difficult to shift. The Shimano 1x11 group is intriguing also because, I think, you don't have to change the freehub.

What say ye?

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[PMK]

Mike, we run older 3x9. We had very few problems with Shimano, but the bike ECDM has been rock solid with SRAM 1:1 XO stuff. Unless you are doing electronic shifting, the XO style is just superior on long cable runs.

As for how many gears, as mentioned, we still run 3x9. No plans to swap it out since there is no apparent advantage.

Depending upon the terrain, will determine the cadence. Yes we are most often in the middle front, but will use the big ring to run the flats, gravel grinder stuff or connecting trails. Our front is a 46t, with a 34 middle.

Our friends Tommy and Martha run a 2x setup and they use the FSA carbon road cranks with no issues on their ECDM 29. They are strong and ride all of it. Not sure what he has on the back but I could find out.

Also consider, you will be faster on the ECDM because the skilled riders can ride better lines to maintain momentum. The Fandango is good, but always seemed to be a gear slower in rough terrain. On smooth terrain it was similar and on the asphalt the it close with the Fandango slighter quicker on the same effort.

In terms you can understand, do your best to gear the ECDM like a 125 with a 6 speed. Always have the right gear, but know you can ride it like a 400 with a 4 speed when needed. Road or off road tandem, I always prefer the best gear and minimize the mashing. Smooth spin always works better. Get's you out of unexpected situations also.

Before we would consider 1x11, we would go internal like a Rohloff. Anything to clean up the back end and effectively make the trail wider lets you carry more momentum. Rohloff also can shift without pedaling, can shift with back pedaling. So say you entered a rock garden, had the wrong gear, you could simply get the gear by some back pedaling rather than trying to shift and mash the pedals.

Are you buying a production ECDM or having upgrades of any kind?

You will love the bike, assume it will be a 27.5 wheel.

 

[ds2199]

We do so much mountain climbing that I am not ready to give up my 22/36 low gear combo. I suppose you could get there with a small front chain ring and 42t or 44t cassette, but then you are spinning out on flats.

We still ride 3x10 (Sram X.9 or X.0 We have ridden 2x10 and still had the same low gear and not too far off of the high gear. We spend most of our time in the middle chain ring or granny, but it is nice to have the big ring on flat roads.

I've heard the electronic shifting is pretty slick. I have yet to try it (mostly b/c I'm sure that I will like and you know what they say about Pandora's box).

On our fat tandem, we have 1x10 (11/42 cassette with the wolftooth 42), I think we have a 28t chainring. It works fine for the snow. I don't spend enough time on a flat road to be very concerned, but we do spin out.

My gut says to me the 1x11 would be pretty awesome MOST of the time. You'll miss your lowest low and highest high from time to time. Also, the jumps on the last few gears are kinda big.

My .02

 

[mhopton]

Thanks for the feedback Paul and Dan. I'm intrigued by the 1x11 but not sure it's the right group for the mtns around North GA. Looking hard at the XT 2x11 group and that may just be the way to go.

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[ebnelson]

We've been using a 1x11, 28T chainring and SRAM 10-42 for around 1.5 years. Definitely not going back to front derailleur set up. The wider cassettes, ie eThirteen and SRAM Eagle would allow for better high speed gearing. We will wait for a steel version with the Ealge gearing probably. We swapped out the rear swing arm for a 12mm thru axle with gives lots of hub options for an XD driver cassette. Our current cassette is a SRAM X1 XG-1180 which is smooth and seems durable.

 

[mhopton]

Good feedback, thanks. After lots of research, I think we're going with either an X1 or GX 1x setup and an e13 9-44 cassette. Hopefully we can get some good mileage out of the setup until SRAM'S mtb etap drivetrain comes out. I think that will be revolutionary for mtb tandem use.

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[PMK]

When is ETap slated for release? Do you need a preproduction setup? I can ask the inside guy at SRAM since it will be on a stand out bike.

 

[mhopton]

Great question Paul - not sure. If you know someone, see what you can find out!

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[ebnelson]

Just ordered a Blackspire 26T for our 76BCD XX1 spider. The 28T isn't cutting it for Colorado high country climbs. The 28T was fine for Moab and our usual rides around Boulder, CO. I'm ordering a TRS+ cassette to maintain our top end gearing.

 

[ebnelson]

We love the TRS+ cassette. Pairs nicely with the 26T chainring. For lower altitude rides, or flatter terrain, I can see using a 28T or a 30T. So far it's a big success.

 

[mhopton]

That's great to hear - thanks for the feedback. We've spec'd SRAM X1 1x11 with the e13 TRS+ cassette. Hope the 30t is sufficient for our mountains along with the 9-44 range, or we'll drop to a 28t.

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[ebnelson]

I should point out that we are using 29er wheels with the biggest tires I can fit.

 

[ebnelson]

We love the TRS+ cassette. Pairs nicely with the 26T chainring. For lower altitude rides, or flatter terrain, I can see using a 28T or a 30T. So far it's a big success.

The Blackspire chainring isn't playing well with our Middleburn XX1 spider. Tolerances to tight on ether the chainring or spider and in addition the Middleburn XX1 spider is too thick for the very short XX1 chainring bolts. XX1 bolts are a larger diameter than standard (8mm) chainring bolts.

I wish Middleburn made a direct mount 28T for their RS8 cranks.

 

[mhopton]

Just a quick update on this post. The new tandem is built with X1 1x11, a 30t front ring and an e13 9-44 cassette. Can't wait for the demo ride tomorrow.

Alex did an incredible job on this build and spec'd the bike with exactly what was needed to suit our riding. It should be a blast!

Haha, the Tandem Master at work!

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[ebnelson]

We have around 10 rides on the E13 9-44. So far, shifts well and seems to be holding up.

 

[moodray]

Hi ebnelson and mhopton,

I'm interested to know if you have any further opinions on your e*thirteen 1x11 setups...

We're also building an e13 9-44, 30T, but with Shimano XT Di2 shifting. Sure would be nice to hear your experiences so far. We were going to wait for eTap to release, but it seems that won't happen in the near future.

Cheers!

 

[ebnelson]

We have two mtb tandems. On our ECDM we run a 26T with the 9-44. This gives us comfortable gearing for high altitude climbs and works fantastic in technical terrain. We are very happy with the 1x except it's easy to spin out descending. Our other bike is a carbon hardtail with a 2x 36T/26T crank and the same e13 9-44 cassette, but with Di2. This bike replaced our road bike so we needed very wide gearing. The Di2 works great with the e13 cassette.

 

[mthopton]

Hi ebnelson and mhopton,

I'm interested to know if you have any further opinions on your e*thirteen 1x11 setups...

We're also building an e13 9-44, 30T, but with Shimano XT Di2 shifting. Sure would be nice to hear your experiences so far. We were going to wait for eTap to release, but it seems that won't happen in the near future.

Cheers!

I've got several hundred miles now on my e13 cassette. I can say that it shifts flawlessly and seems to be wearing well. The only issue hat I've had is that the lock ring on the cassette has loosened a couple of times. It's been re-torqued and loc-tited again, so hopefully it holds this time around.

Overall, very happy with the cassette. We are running a 30t ring and the 9-44 cassette.


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[laksboy]

My new to me tandem came with a brand new 10-spd 11x40 and a double. I converted it to a 1x with a 30t oval chainring. Gearing is just barely low enough for us. There were multiple times I called back the stoker while grinding up a climb, "Do we have any more gears left??" I was just checking Sun Race's product offerings and they also make a 1x42 and a 1x46... Once we wear out the 1x40, I'll certainly go for the 1x42 and might consider going for the 1x46. I've always hated gappy gearing on my single bike but on the tandem "gappy" just works better in our terrain. On out old 2x9 set-up on our previous ecdm, I was always shifting 2 gears at a time when decelerating up a hill. Now its back to a more normal shift rythem of 1 gear at a time like on my single bike.

 

[Hurricane Jeff]

I use a Sunrace 11-46 on my 1x single bike, actually the gearing isnt as gappy as you would think.
So you converted the bike to 1x? I was going to do that but only conern was not having enough on the top end and/ or low-end.