2013 Shimano Dura-Ace Di2 9070 group on Trek Madone Project One road bike

The fine folks over at Race Pace Bicycles claim to have just put together one of the first bikes in the US with the new Shimano Dura-Ace Di2 9070 group, including the new internal battery. And they sent pics!

Thus far, we really haven’t put eyes on the new internal SM-BTR-2 battery. It was subtly announced alongside the Alfine Di2 and mentioned again when 9070 was introduced, but neither time did Shimano include photos. And when we saw a bike with it at NAHBS last year, they wouldn’t let us pull the post for examination.

Nick at Race Pace’s Ellicott City, MD, location said when they ordered the bike from Trek they were told the internal batteries weren’t shipping yet, but then it showed up in the box! Pics and details below…

The battery comes with several “slotted leaf spring” adapters and shims to fit different size seat posts. Once the right size parts are installed, an O-ring slides on them to lock everything in place.

2013 Shimano Dura-Ace Di2 SM-BTR-2 internal battery

Normally, the battery mounts inside the seatpost and enough slack is left in the wire to allow the post to be removed without yanking it loose…which would mean plenty of finagling to get the wire back out of the frame.

In this case, the battery placed in the seat tube rather than the post because Trek Madones use an inverted system where the post topper slides over the seatmast.

2013 Shimano Dura-Ace Di2 SM-BTR-2 internal battery on a Trek Madone Project One Road Bike

Fortunately, Shimano had the foresight to add an external remote charging port on the control box.

2013 Shimano Dura-Ace Di2 SM-BTR-2 internal battery

A couple more closeups.

2013 Shimano Dura-Ace Di2 SM-BTR-2 internal battery

2013 Shimano Dura-Ace Di2 SM-BTR-2 internal battery actual weight

Actual weight is 56g, roughly 15g lighter than the standard battery! Nick says Shimano told him charging time is about 90 minutes and has the same battery life as the standard battery. Win-win-win.

…and some general group shots:

2013 Shimano Dura-Ace Di2 SM-BTR-2 internal battery on a Trek Madone Project One Road Bike

Note how much smaller the 9070 Di2 is than previous generations – all thanks to smaller motors.

A carbon fiber cassette “spider” is a first for Shimano. We showed you its backside in our “Unboxed & Weighed” post, and here’s the inside.

HUGE thanks to Nick for sending this over!


  1. Concerning “going pro” this isn’t about pushing that gear, it is about aesthetics. If you are taking the time to photograph something and put it on the internet to be viewed by others you should take the time to put the chain in the big ring/small cog and have crank arms in line with the chain stays. Just because you work for a bike shop or amateur blog doesn’t mean you shouldn’t know how to take a proper photograph, because once it’s taken and posted people are going to look at it and you should be respectful and appreciative of that.

    Throw up in the toilet, not on the sidewalk.

  2. Wow. In a story about Shimano’s internal battery, what the peanut gallery latches onto is the chain on the small chainring. Wow. That doesn’t speak very highly of the audience.

  3. What do you want guys want us to say?
    I have a hard time getting hyped about a battery mounted in a seat tube or post. Maybe it’s just me, but there isn’t exactly anything groundbreaking or game changing to see here. As such, I will continue to post comments that the stem should be slammed and the crank should be setup properly to photograph. In its current setup I imagine the bike fitting a T-Rex quite well.


  4. It’s probably being setup for a local doctor or lawyer type. If I could afford it, that’s how my bike would be setup for my riding style. Not everyone that rides a bike is a CAT whatever racer wantabe.

  5. that’s definitely a Domane. and this makes no sense because previous generation Madones/Domanes had a molded cover on the seat tube stub. unless trek redesigned the integrated seat masts specifically for the internal batteries idk how they would get the batteries “inside”

  6. curious how long that battery will take before it falls down the seat-tube on that bike. I don’t see how they could have inverted it and feel confident it wouldn’t come loose after riding. Probably not the best bike to implement an internal battery like this.

  7. Just enjoy the fact someone took the time to make an article. No one cares if it is in the bike ring on not. Half you chooches run SRAM and the other chooches are too cheap to buy the new group anyway.

  8. @Quickie – You’re right, battery powered groups “aren’t” game changers? I guess cool stuff like rim brakes and cork bar tape is, LOL…
    @James – You’re a bag!
    Bikerumor, keep up the good work and keep sending us updates of the new, stuff we want and are buying. Well most of us are…

  9. @johndoe

    Domane 6 series in my shop has open tube for the seat mast so installing this would not be a problem.

    @Quickie, you pedantic git, who cares which ring its in. Also stem stack is a valid set up adjustment to suit the rider, and when selling a bike its usual practice to leave as pictured, as moving the spacers over the stem looks really daft, and you don’t cut down a steerer unless the customer has asked for it.

  10. @Bogwolf, This is a beautiful bike and it looks like (deleted). Time should be take to cross the T’s and dot the I’s so that the true beauty and engineering can be appreciated.

    PS, Im not a trek fan boy but I do like nice bikes from all manufactures

  11. Next we can all criticize the order and arraignment of the Gu packets on the shelf and mourn the fact that the left edge of the rug extends past the corner of the slot wall/counter. And the parts scale isn’t square within the picture; what will we do???

    I usually pose bikes when I photograph them… but it really doesn’t bother me if other people don’t. Seriously, who cares. This isn’t in a catalogue or on a dealer website – it was taken quickly in a shop by an employee who has far better things to do than catch hell from a bunch of picky commenters online.

    Be glad they took the time to send the info and pictures to BR so we can have the article.

  12. Seriously, they don’t even have the presta valves next to the floor so the tire brand is parallel to the ground, what a bunch of amatuers.

  13. Im with Marino and Murdock on this one. Some show love, some mean mug. Some choose to hate, pop tailgate. Murdock for president.

  14. Glad at least some of you liked the pictures of the new Dura Ace electronic group. This new Domane 6 series weighed 14 lb, 14 oz before pedals, it’s a sick bike. Cheers

  15. You internet White Knights need to come off it. The point of the pics is to show it off in the best possible light and drive excitement for the product. OF COURSE people are going to pick up on it if the obvious things are missed.

  16. Cool battery, Ugly a** bike. (Or rather the setup…) Why bother riding a race bike if you’re going to sit like this anyway.

  17. One thing to add to this as we just got a Madone with the Dura ace Di2 on it is that the charge cable that the customer gets wih the bike also doubles as the cable that will let you hook the system to your home computer and download the E tube project software to set and adjust the settings of your Di2 (multi shift speed and how many gears it will do 2, 3 or all. Plus do some fine tuning of the front and rear der’s also) It will not let you diagnose a problem you will need the pce1 box for that.

  18. It would look a lot nicer with some Campy carbon cranks… Shimano is going to a carbon spider carrier for it’s cassettes but the crank arms are still alloy? It makes no sense!

  19. Concerning weight, I received similar bike this week taking the options for lighter handle bars and saddle. Weight without pedals for my bike (58 cm) is 14.75 lbs (6549 gms).

  20. I hope somebody can clarify something for me. Review states “Note how much smaller the 9070 Di2 is than previous generations – all thanks to smaller motors.” under a picture. I have been told that to date there has been only 1 version/generation of Ultegra Di2 derailleurs (front and back). Please let me know what is accurate. I am going to build a bike with Ultegra Di2 so want to know if I have to worry about which generation I am purchasing if that is an issue. Thanks.

  21. I found this article a while ago just after I ordered a Dura-Ace 9070 group to replace the 7970 kit I have on my 2012 Madone 6.9SSL. I’ll be glad to get the battery out from under the bottom bracket shell and put it inside the seat mast. I received the new kit yesterday and I felt like a little kid on Christmas morning as I opened the box and looked in awe at all the beautiful parts!
    However, I was a bit disappointed when I opened up the box for the internal battery and found that it only came with an adapter kit suitable for installing it in a standard 27.2mm diameter seat post and not the fancy adapter that was shown in the pictures that were posted in the article.
    Does anyone have any details about the adapter shown in the pictures? Is it available through a Trek Store or is it from another company? If you can help out with a supplier name or part number it would put me one step closer to getting my project underway.

  22. Hey Don, Did you fine the adapter for the Madone, as seen in the picture, I also require one of these to fit my 6.9

  23. I’m in love with my seat post battery! I’m not a Dr. or lawyer, just a serious biker who lives below my means so I can ride what I want. Some of us average “Joes” have biking priorities.

  24. Hello, I have been looking up sources that say that the internal battery is only compatible with specifically designed seatposts. where did these people get those inserts?

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