Confused about Di2 wireless
 

I guess this is a pretty simple question that I can't seem to figure out. When I view new bikes with the latest Ultegra Di2 they never seem to show the wireless unit under the stem. Is this something I would need to buy in order that it would work with my Garmin and Smartphone? Does it come with the Di2 purchase? I was hoping to have this functionality and not have this wart hanging below my stem.

Thanks,
TMT

The below stem wart is the 11 speed junction box / charging port / config button.

11 speed Di2 - Bluetooth wireless is an add-on option. It permits software updates and displaying gear selection on a bike computer.
Brifters/battery/junction box/derailleurs/(optional D-Fly Bluetooth) all hard wired.

12 speed Di2 - The Bluetooth is built in. Plus the brifters do not require being wired to the battery/derailleurs.
battery/derailleurs are hard wired.
Brifters, hard wired is an option. If used wireless, be sure to keep spare coin cell replacements.

The 11 speed stem junction box had no wireless function and no longer exists for 12 speed.
It was also available as a bar end device and a frame mounted device.

Barry


BTW - The above does not take into account the new 105 12sp Di2.
It’s brand new and may offer different functionality.

I know you said latest, but which latest? The 12 speed Di2 or the 11 speed Di2?

Just like anything else, you have to know what model and version of Di2 you are talking about. For the last few versions of 11 speed Di2, it can be fully contained inside the frame and bars of the bike. If you didn't see the LED's and button neatly slid into the end of my right handle bar end, then you would only know it's Di2 from looking at the DR's. All 11 speed Di2 requires an optional component to be purchased to have wireless functionality with other things such as your Garmin or other device.

I bought a EW-WU111 to use with the Di2 on my Tarmac. I connected it as the first connection inline to my battery which is inside my seat tube. Being a carbon bike, I haven't had any issues with it being seen by my Garmin on the handlebars. Haven't heard if others with aluminum or other materials for their frame have issues doing such.

12 speed Di2 has the wireless included since it doesn't connect everything with wires.

A new bike with a "Wart under the Stem", it can only be 11 speed.
There are no 12 speed warts. :)

Barry

My Di2 bike is eleven speed and 2 years old. It doesn't have a "Wart" under the stem. So also it will be true that not all 11 speed Di2 bikes have warts.

I'm only assuming "wart" means the Di2 junction A which was entirely external in the early 10 and 11 speed versions of Di2. My 11 speed Di2 came with the EW-RS910 junction A that goes into the end of the handle bar. All you see of it is the button, LED's and connection port for diagnostics and charging.

I suppose I'm most surprised that any new bike will still have the wart under the stem. 11 or 12 speed. I have trouble imagining a bike with out drop bars. So that might be an issue too! <grin>

TMT goes on to refer to this as a "Wart"

The OP is specifically asking about a bike "with" a wart.
You queried him as to 11sp or 12sp

I simply stated - - - - - - >> new bike wart = 11sp

Have a nice day

Barry

I think Shimano only gives you a wart with 12s Di2 and rim brakes. With disc brakes, you are spared. I could be wrong.

See, I learned something... it's not a "wart" but a junction box. I thought it had some other function i.e. BT antenna or something like that. Live and learn.

There are at least 3 variations of the A Junction box. Original model mounted under the stem. Next was as a plug in the handlebar end. That required the bar to have holes for the Di2 cables to exit the bar and route into the downtube enroute to the B Junction. A later version mounted into a downtube spot. All the A junctions had either 3 or 5 ports (not sure bar end had 5) for the 2 shifters, plus extra shifter buttons for sprinting or climbing positions. Time trial bikes as example might have 4 shifter buttons, on the end of the aero bar and near the brake levers. With the new wireless Di2, they've done away with the A junction as the shifters talk directly with no wires. Theres also an A Junction box designed for mt. biking which is a combo gear position indicator, BT wireless transceiver as well as 3 port junction, it mounts onto the handlebar next to the stem,

The downtube and bar-end junction are the same junction, actually - they're both EW-RS910 ;-)

Also.. while 12-speed rim brake bikes do not feature 'wireless shifting', they also don't have a 'wart' or junction near the stem. The rear derailleur is still the only junction :).
(but yeah.. you could build a 12-speed bike with a (b) junction... but you don't have to use one)