Firefly :: XCr :: Integrated Di2

This stainless steel XCr bike has been built with internally integrated wiring for Shimano’s top of the line gruppo called Dura-Ace Di2. It uses a battery to power the front and rear derailleurs, making shifting slightly more precise than with traditional cables and housing. To make this bike even more awesome we hid the battery system within the frame, normally they are mounted externally in an ugly (not so little) black plastic box. The battery we put in this frame is lighter and lasts longer than the standard battery that comes with the gruppo.

This is like a frame from the future, with wires all over the place on the inside. But with only minimally exposed wires externally, making for a really clean looking built-up bike. We made specific purge holes inside the frame a little larger (per Shimano’s spec) to accommodate the internal routing.

We also bead blasted a titanium stem and seatpost to match the finish of the bead blasted XCr stainless steel finish of the frame. If you look closely you will notice the slight difference in color of the raw finish of each of the different materials. The stainless is a little brighter while the titanium has a warmer and softer look to it. These two pictures (above and below) make an excellent comparison of the subtle differences between the two metal’s finished surfaces.

Each of the threaded waterbottle mounts (aluminum blind riv-nuts) are radiused to the diameter of the tube they fit into with a special die Jamie made for the installation device. This mechanical means of attachment is usually considered enough, but we go the extra mile and bond them in with aerospace grade epoxy while we are bonding in the fiberglass seat tube insert. The seat tube insert (not pictured) is a little more than just regular fiberglass, technically it is a mandril rolled 7781 fiberglass weave in 250 degree epoxy curing resin… in case you were curious, which you probably weren’t, but you wouldn’t know unless we told you about these things.

Due to the high stress areas where the Di2 wiring ports are located we reinforced the hole with an XCr washer that we silver brazed to the tubes.

The rear derailleur wires exit through the chain stay endcap via a 7mm x 8mm hole and supplied grommet.

But the sweetest thing about this frame was saved for last… The battery is in the seat post.

Pop it out, plug it into the charger, pop it back into the frame and hit the road!

16 Responses to Firefly :: XCr :: Integrated Di2

  1. I hope you charged Drew an arm and a leg for that. It is amazing.

  2. Alan b

    Cant wait for mine. Amazing work

  3. Awesome, I can’t wait to ride it. Thanks for the attention to detail guys.

  4. Glenn M

    Amazing work guys, you keep setting the bar higher with each build

  5. joe

    Holy doolie.

  6. Daniel

    That’s just too cool!

  7. Adam Jones

    Sure would be cool if there was just a little plug that stuck out of the top of the post so you didn’t have to take the post on and off the bike. Just a thought…

  8. Derp

    Any chance that Firefly will ever make some Ti accessories?

    As a certified Di2 mechanic at a very large Giant retailer in Castro Valley, CA, I can honestly say that this frame is awesome for the application.

  9. Bobby Earle O'Brien

    Wow! Stunning, as is all your work! If I didn’t love both my Rhygin Metax road and CX bikes (coincidentally, stainless steel bikes that were made in Boston), I’d be taking the plunge. Must resist….

  10. Could you tell me what color is that King Headset? Is that the Steel finish only offered to Builders?

  11. NickV

    What brand/model is that Seatpost?
    Amazing frame by the way!

  12. Bill

    Wow, it’s awesome that we titanium-buffs in Taiwan got All-Four Cycling to be the dealer for you guys’ amazing works!! By the way, what are “fiber glass seat tube inserts” supposed to mean? Are thay water bottle mounts on the seat tube?
    Thank you guys for creating these wonderful frames!!


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