How does Shimano Di2 Actually Work?| Electronic Shifting 101

Electronic Di2 Shifting is commonplace on high end, and even mid-range road bikes now, but how exactly does it work? Alex explains the basics of a Di2 groupset and it's workings, including clever tech borrowed from the car industry!
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[@gcntech]

Did you find this interesting? What else would you like us to look into? Let us know in the comments 👇

[@Doniyorbek_Turgunov]

Info about binary code which flowing between batt and junction looks very expired...sorry...))

[@danjdavison]

I want to see the derailleurs taken apart, and know exactly how the motors work in them

[@CyclingLifePT]

I'm sticking with mechanical. About once a year a cable snaps while travelling and all i have to do is replace the cable which is light, easy and quick to fix. I dont have to worry about recharging my bike and be afraid of system failures. I would appreciate some electronic levers, something that could be overriden if there is no battery, but also something that could be acted upon with more confort from the tops (by adding a set of buttons to the tops, the same way they have buttons for the time trial bikes)

[@danjdavison]

@@CyclingLifePT I’ve worked in bike shops for 8 years, and I’ve never seen anyone have an issue with Di2. Also, you only have to charge your bike every few months, so if you can charge your phone every day, you’ll never run out of battery with Di2.

[@KenSmith-bv4si]

#AskGCN, Does the FSA K-force We operate the same as Shimano Di2?

[@donnasmith1602]

As I am aging, my hands are starting to get some arthritis in them, so am now seriously looking at switching to Di2 so that I can keep riding with less pain. This was a very helpful video. Thank you.

[@Imnotplayinganymore]

Ditto Donna! Let's show those kids some real grit. Aging is not for the faint of heart. Keep riding, we'll never die!

[@nathan-ls8yw]

have you thought of getting the specialised diverge? the suspension could help

[@shanebibby4255]

Likewise Donna just moved onto di2. Absolutely fabulous 100% right decision go for it 👍

[@Dan_Soundgar]

I have way more issues with hips and knees than hands, I have been trying to use the Osteo Bi-Flex to try and get to a more appropriate retirement age.

[@gbart981]

I've always admired bikes for their simplicity. I've ridden bikes as transportation since the 70s, watched tech change. I feel bikes should be affordable, easy to work on and modifiable. I have never been stranded because I couldn't get my bike back in working order with the tools I carry with me. Nice electric stuff but feel it doesn't meet the ease of maintenance mechanical systems afford, certainly not as cheap for us working stiffs.

[@SixSioux]

I think Sram Etap fits perfectly your description, unfortunately is Still stupidly high priced.

[@Alex-kr7zr]

Agreed. On the contrary, electronics are a lot more durable and maintenance free (not speaking about consumer electronics here). Considering that the shifter is a very common problem source in bikes, I'm curious to see how the electronic shifters will hold up over time. The pricing is still a bit high atm though. Working as a roboticist and also in the automotive industry previously, usually choosing a solution follows that order: software, electronics, mechanics. So I'm actually very pleased to see electronics entering the cycle market, it will be a matter of time until software follows, and we will have all sorts of software based tuning.

[@switch6690]

​@@SixSiouxI'm far from being a Shimano fanboy, but SRAM eTap is exactly the opposite of being simplistic imo. In fact, I think it's one of the worst products ever designed: Modern road biking already needs way too many batteries being charged, and having 4 additional ones for my shifter alone doesn't make it better by any means. There's a good reason why cabling in vehicles exist; nobody would even think about charging each backlight of their car individually. But in the bike world, for some bizarre reason, such annoyances are totally accepted and even desired. A good Di2 cabling can easily last more than a decade only requiring a single battery, and I really hope Shimano sticks to this way superior approach.

[@c7dermatome]

I don't race bikes any more, spend all my days on computers and/or fixing electronics. Was a bit suspicious of electronic gear shift at first, but honestly I think it's superb, have seen the electronics inside the housings (trust me it's very hard to get at for good reason) and I would be confident in saying that what Shimano has invented is near infallible. It's great that the connectors are all interchangable and wires are 2 core (these are maybe the only bits that might get broken easily and bieng this way are easy to fix and replace) Thankyou for such a great series of videos on Di2

[@grahamballard7041]

I’m sticking with mechanical as I simply can’t afford to upgrade to di2

[@htmonaro1969]

The CAN BUS system has been used by model train systems for decades, it called the DDC. The tracks carry bot the electrical power to drive the motors and the digital signal to tell each train how to behave - go slow, go forward etc. It's incredibly simple yet also technically sophisticated.

[@glenlarimer1358]

Very interesting program, Alex (and staff)! What you said about previously being an auto mechanic is exactly why I don't want electronic shifting or disk brakes on my bike. I don't want to be an auto mechanic! I like having a very simple set of tools along with me on a ride, confident that I can repair any small problem and be on my way. I don't want to worry about batteries or bleeding hydraulic cables, etc. should something go wrong.

[@tonyjones9442]

Underrated comment.

[@mysterious_czrs]

Dude suspention is when the servicing nightmare begins

[@amaclach]

Is that why you drive a car that is hand cranked, has a carburetor and a distributor? Di2 is pretty reliable. Mechanical systems have their own issues.

[@erik_midtskogen]

Thank you for that. Just one minor technical quibble: CAN stands for "Controller Area Network", rather than "Controlled Area Network".

[@roshinsoni]

Shimano uses a proprietary communication protocol called E-TUBE in their electronic shifting systems, specifically in their Di2 (Digital Integrated Intelligence) systems. While E-TUBE is a digital communication system, it is not based on the CAN bus protocol. Instead, Shimano's E-TUBE platform provides seamless communication between components, allowing for precise electronic shifting, customization, diagnostics, and firmware updates through the E-TUBE app and software.

[@FinlayDaG33k]

"high tech communication protocol" Oh stop it, you made my desk light blush :3

[@douggerard3411]

As the prices come down I am more likely to adapt to the Di2 system on my bike from a mechanical Ultegra system. I like the idea that the derailleurs won't get out of adjustment due to cables getting old and make shifting a little more secure. It is not a good time when my chain falls off the big ring when I shift up on the front derailleur, which happens no matter how much adjusting I do to it.

[@mikeshaw714]

Brilliant description, i actually thought the system was wireless. Regarding CAN, I write firmware for a living on CAN based systems and it’s not the easiest thing to explain to people so you done a good job there.

[@Cammboz]

Hi Mike, do you know how the power supply and data share the same wire, would be an interesting detail for general to add

[@mikeshaw714]

@@Cammboz kzbin.info/www/bejne/ep3ZipKNZ5eJhMU It's a bit techie but worth a watch.

[@Cammboz]

@@mikeshaw714 interesting, thanks. I guess the power in the di2 system must be derived from a higher potential difference between the high and low wire.

[@paulallen6378]

CAN bus usually has differential signal lines (high & low), presumably Shimano have a proprietary implementation for their system with only two wires - one with ground and the other with the supply voltage that also has the signal on top? There will be less electric noise than in a car so the differential system is less important.

[@gerardotelese5337]

Still feels like something from another geological era compared to the SRAM wireless system (not thinking about how well the idea is implemented and function, rather only about the idea behind the product). Feels like they just changed a lot of cables for a lot of wires.

[@adamsteineke4661]

Except the wires don't stretch like cables do, I'd also prefer to charge my internal battery a few times a year versus having to remember to charge multiple batteries for each ride... that said, it is a lot less cabling to deal with!

[@neil7769]

I have Campy EPS which also uses wires. I can't really see what the advantage is with wireless THB, except that it's easier to install. Once it's installed, who cares if there are wires inside the tubes? And you just have one thing to charge and never need to worry about pairing / connection issues.

[@zachm.3049]

@@adamsteineke4661 battery wear and electric dependency is not an improvement. Shifting mechanically is way better, gives more feeling to the gears and provides faster control than electric could offer. But hey, if it makes you happy. Go for It. I was hoping this video explained the DI2 shifting mechanic in detail, So I could use it on a IGH-8 speed or IGH-11 speed Alfine using mechanics only, to shift old style without electric. Not sure if this combination is possible, so still hesitate what to buy for IGH.

[@erik_midtskogen]

@@zachm.3049 That's what I used to think about electronic shifting. Then I bought my teammate's time-trial bike, which was outfitted with Di2. Once you get used to that, you're spoiled. I once got dropped in the Grant's Tomb Classic (a late winter crit race) when my mechanical shifting acted up in sub-freezing weather. Di2 just works, instantly and smoothly, every time, under any conditions. No more fiddling around with it constantly when temperatures change or cables stretch. No more afternoons spent threading internal cables through frames a couple times a year. The mechanical shifters and derailleurs on my main road race bike are worn out now. I'm replacing them with Di2--if and when my LBS can track down the necessary parts. I'll be doing more riding, and less fiddling around. I can't wait.

[@erik_midtskogen]

@Gerardo Telese I've learned not to trust anything too important to wireless technology. I could picture riding alongside other riders with the same groupset and the systems interfering with each other. Wireless systems generally don't depend on using different frequencies to isolate from each other, but rather, different IDs in network header packets. When several of these systems are used in close proximity, it gets harder for the electronics to filter out the content from the noise generated by nearby wireless networks. For this reason, my whole home is wired except for the few devices that lack an RJ-45 socket, and require wifi to operate. My wired stuff always works, while my wifi-only devices suffer from frequent dropouts and generally unreliable operation.

[@philrobson7976]

I still don’t know how the dérailleurs move. Magnets? Motors? Where’s the power? Let’s deconstruct the units now.

[@bengarside79]

They use servo motors

[@antonhelsgaun]

@@bengarside79 thanks. That was all I was looking for

[@einundsiebenziger5488]

@@bengarside79 That's exactly what this guy could have explained instead of binary coding.

[@fepatton]

I wanted to add a Bluetooth module to my Di2 setup and was fretting over how I would get it to work until I realized the setup was a CAN bus, and it would just work. All I needed was a junction box and short length of cable. Bike is now Bluetooth/ANT enabled, and I can control my Garmin with the top buttons on the hoods, and get gearing and battery data on the screen. Cool!

[@alexanderkoch4830]

The only shame is, that it's not included by default and they charge a fortune for the short cable you need in addition.

[@PaulJWells]

Great video. Gave me the information I needed (in practical terms, it doesn't matter which cable goes into which socket on the junction box) I'm running an unusual, but supported configuration of Dura-Ace drop levers with an Alfine 11 speed hub gear on my tourer. Just upgraded a five-year old bike to have Bluetooth connection by replacing the original A junction with an XT indicator (Sc-mt800) It was child's play to fit and works perfectly. Shimano really have provided us with an amazing technology.

[@georgelloyd6183]

I really enjoy having the Di2. It is an amazing piece of technology.

[@davemillet1502]

Great explaination, only been riding Di2 for about 6 months and helps me understand why my firmware updated and how I can change what each shifter does. Now just have to remember to charge up every month or so as lost power to front as battery dropped below 25%.

[@izi941]

FD works until 4% Battery capacity...above 20°C that equals 2-3h easy riding, or 1h in racing environment. (Depends on profile/nr.of shifts)

[@devononair]

@@izi941 2-3 hours? That's not very long at all!

[@dennise1816]

Mechanical shifting has worked well for my 50 plus years with Shimano Dura-Ace. No reason to change

[@Jeebus0143]

Thank God the entire world does not think like you otherwise we wouldn't have so many benefits that technology has brought us in every aspect to life.

[@einundsiebenziger5488]

What about the electric motors inside the shifters and their power supply? Would have been much more interesting than "Can Bus" and binary code.

[@Wksfr]

Agreed! The magic is the accuracy and strength of the motors, most people can appreciate clicking a switch sends a signal, no need to waffle on about binary nos.

[@mauricetremblay1324]

With the videos you have posted I now want a Di2.

[@stevederr4927]

Love my di2! Love having it talk to my Garmin. It's great to be able to see the di2 battery level on the Garmin. Even better to be able to see what chainring your in and what gear you are in on the rear derailleur, right there on the Garmin, no need to look back. I also run my in semi synchronized. I'll never buy another bike without di2 or SRAM equivalent. Would you do a video on the pros and cons of running the di2 in manual, semi and full synchronized? Would also be nice to run through the software.

[@mrcstb7479]

Hey Steve, which Garmin device do you use? Thanks!

[@stevederr4927]

@@mrcstb7479 I have a Garmin 520, but it is my understanding that Garmin, Wahoo and Karoo all communicate. I did have to buy a Shimano ‘interface’ item (~$100) that is connected inline on the dI2 cable. Best $100 I ever spent. I love knowing my dI2 battery level and what gear I’m in both on the front and rear derailleurs.

[@CarlosSanchez-no7nk]

SRAM AXS for the win! Getting rid of the wires/cables is the best thing that happened within shifting tech

[@nickjohnson710]

Yeah looks cool but the quality of shimano is better and haven't you heard that shimano have wireless durace and it's in 12s been seen on remco's and a few more pros bikes

[@nickjohnson710]

@@jonoharper4729 " come on man ' you sound like creepy joe Biden?!? I go back to my original point the quality of shimano parts are better.....I had many sram parts on my 29r and high end stuff and was disappointed with the build quality and the feel of the shifting and everything wears quickly.......give me shimano any day

[@nickjohnson710]

@@jonoharper4729 plus my LBS has nothing good to say about sram

[@nickjohnson710]

@@jonoharper4729 👍

[@AlainSTO]

I must be the only one who finds this easier when it comes to maintenance than mechanical shifters. Adding pros and cons to this video would've made it perfect for me.

[@Alex-kr7zr]

Of course, it is. That's the reason why electronics have replaced almost everything in the automotive industry, for example. Over time, this will also be cheaper to produce than the mid-range mechanical systems.

[@pavelhornicek554]

Great video, simple and useful description. I am looking forward when I will have electronic shifting.

[@luigicolbni5345]

you ignore campagnolo drive trains like you ignore traffic lights :)

[@user-ni2sc3me6x]

Many thanks for this informative video. Just purchased my first Di2 bike and excited to learn more!

[@tristancamp-lagueux6562]

Can you do the same vid but for Etap?

[@thegingaman]

Two out of Seven are Di2 and are planning my TT bike to be converted to Di2 next. I'd have Di2 on them all if I could.

[@mackie4323]

Im a new rider and I did not know that the bicycle I ordered online comes with an electric shifter. Having seen this video made me aware how it works. Thank you! I still have not decided wether I should stick to electronic shifter or go back to manual. I will update my post in 25 days after I rode my Grizl enough.

[@andrewbrowning6947]

No mention of bluetooth module, programmable hood buttons, different shift modes etc

[@djiembefola]

It's very expensive. However, I like the ability to easily run mountain bike derailleurs with road brifters, smart shifting patterns to avoid extreme cross-chain gears, etc. I like the idea of wireless, and am not crazy about running DI2 cables internally when doing builds and upgrades. Time will tell if 105 Di2 is really going too be "affordable"......

[@srpskihayk]

I thought Di2 was wireless, or I'm thinking of something else. I have learned that to upgrade my existing Ultegra group set to Di2 will cost the equivalent of another Ultegra group set! All that gets swapped out are the mechs and shifters. Wow!

[@bossg2817]

Only sram etap is wireless.

[@vvictoria6214]

I cycle a lot myself and watch cycling races on TV, but since electronic shifting, much more shifting problems, used to be almost non-existent befor !

[@J88HNT]

I have both SRAM RED AXS ETAP and Shimano Ultegra mechanical. I changed the gear cables recently for new ones on the Ultegra set up and the shifting quality became so buttery smooth again. There is something about mechanical shifting that makes me feel more connected to the bike. Don’t get me wrong electronic shifting is second to none but where it gains in terms of efficiency and performance, I think it loses the true essence of what a bike is.

[@5speed735i]

Nice explanation of CAN bus! Another explanation that I use is: Imagine your name being called out in a crowd that you are in; everybody in that crowd hears that name, but only you respond to it. Furthermore, if you hear another person's name, you won't respond to it, even though you did indeed hear it.

[@openwheelracing88]

No reason such system can't be affordable.

[@MrBJPitt]

It is, compare di2 ultegra to sram force axs

[@Fatbutnotflat]

"high tech".. as in bike companies intentionally putting electronic shifting on top ends only.. better to wait for chinese electronic conversion kit

[@MrBJPitt]

@@Fatbutnotflat you'll be waiting a while. In the meantime, I got ultegra 6870 di2 minus the cranks for $500 on FB marketplace. And dura ace 9150 minus brakes and cranks for $700 on FB marketplace.

[@roythearcher]

"Affordable" is a very subjective word. If you can't afford it it's not " affordable". Cheap is a better term. But this system is by no means cheap!

[@pedrolahoz]

Rides of Japan. Has a very comprehensive, practical explanation for those who want to do their own di2 installation.

[@aspenwagon04]

Its refreshing to hear the term "binary" in the correct context here. Thanks.

[@tonyjones9442]

I sef identity as a hexadecimal human.

[@quesoner34]

Got Di2 on the Monstercross running about 3 years now, flawless! Connects XT mech to road brifters, No seizing cables, Shifts perfectly and reliably EVERY time, seldom needs charging (unlike wireless sistems), Shifts super quick in any situation (under power etc.), Needs virtually no maintenance, As you can tell, I love it. If you can afford, buy it. It is so good, it will just make you forget about it. Which is what good components do.

[@scotthamilton1054]

I’m slightly skeptical only because I like to keep my bikes forever and I wonder how, in 10 years, will the stuff hold up or if the specific version will become obsolete. I have bikes from the 80’s and 90’s that still work amazing and haven’t needed any maintenance at all. I guess I’m an archivist and with new computer based mechanics I question the longevity. Also if I crash and damage a rear mech the ala cart replacement costs is huge.

[@wescoleman6390]

I'm sticking with mechanical shifting on my road bike for the foreseeable future. It's less expensive, easier to troubleshoot, and it's one less thing I have to remember to charge. Forgetting to charge my head unit or speed sensor is merely inconvenient; forgetting to charge my group set can end a ride. I might change my mind if I had to manually adjust out front mech rub on highly cross-chained 13+ speed group sets.

[@ImranWorldCyclist]

I used to stink the same until I rode with di2... it’s a game changer. The battery lasts a very long time and the battery level can communicate with your bike computer so you know where it’s at!

[@AlejandroMallea]

It would be very interesting to know why is it that electronic shifting is supposed to work better under stress, for example at low cadence on a steep climb while pushing high watts. I can only imagine that the force the derailleur applies to the chain as it moves is way more even with an electronic system, as a mechanical system will have a transient or peak until the first few links engage, at which point there should be a lower feedback going "back" to the levers. This would be particularly true while shifting "up" to a lighter gear in the cassette while going very slow, though of course intuition and physics don't always go hand in hand. So Alex or Ollie, I would really appreciate it if you could unravel this mistery! (Alex might need some science glasses though)

[@herculesmclovin]

I absolutely love hearing people answering these types of questions, I'm nerdy in this way too. I hope someone can come along with a good tested theory for us!

[@herculesmclovin]

I follow your idea.. The force being applied must alter along with the force coming back from the chain, to keep it in a precise force range for the smoothest transitions. That has got to be more rapid and precise than us.. Because we receive feedback from our feet on the peddles, through to the legs etc and by the motion of the bike. That then has to be processed and turned into a correction of force output, which by then.. *clunk* awh not again!!

[@amilcaresada7778]

Wow, that is great content. Good Job Alex!

[@j-pella4087]

Wonderful video keep up the great works 💪

[@racovert1]

This was great. Simple explanations with a good visual display. What are the chances that we see a wireless setup soon?

[@normanyang7939]

As a E/E Architecture engineer of automobile. Honestly, although CAN bus is considered as a stable bus system, i still think it's a little over design for the Di2, bicycle shifters don't have that much of the information to transfer. Admittedly, CAN system might could save 2 power wires and a ground wire compared with conventional connections, but it need a modem to deal with the D-A signal. which is also extra weight.

[@thompson9451]

Love that Alex goes all the way down to bin explaining how di2 works lol

[@chrisspeksnijder1717]

Two bike in the garage. One with, and one without Di2. Both are very nice to ride with...

[@IFrancyISantosI]

really makes me love SRAM AXS system

[@stubbietubbie]

That was genuinely interesting. So, a general overview of the other electronic groupsets next, yes???

[@user-cx2bk6pm2f]

This is great, Alex. Very interesting and well done.

[@cobaltpica]

i have always wondered which cables goes where and which junction box needs to be installed. Thanks for confirming that it doesn’t matter. To simplify things even further the Di2 system and its wirings are just like a municipal water distribution and its piping.

[@Livlifetaistdeth]

I'll never understand why you would render the greatest mechanical creation of all time useless without a battery.

[@oioi909]

This is my feeling too. I am fascinated by the Di2 system but something has been holding me back for years, its the idea of batteries, It just destroys the purity of it. A sort of desecration of the whole idea of the bicycle, its perfection, the mechanical art of it. And there is something else which holds me back from buying one - we are being told indirectly that its an improvement, by the mechs being 2-3x the price, for a problem that doesn't exist. Seems like a sort of snake oil, and I would feel a little bit like a sucker if I fell for it. That said, no problem with choice, its up to each of us, the Sram idea seems best because there is a clear advantage provided, no cables. I can kinda see why that would be a good thing, less to go wrong, and less hassle to fit, and the batteries within easy reach.

[@dudefella420]

@@oioi909 spoken like someone who has never ridden di2. It’s just better. It ruined mechanical shifting for me.. I could never go back. And I only charge it once a month, which is more often than it needs.

[@oioi909]

@@dudefella420 Well I did say I am fascinated by it , been riding road since 1987, I like classic bikes but am not against progress, quite happy with my 7800 Dura Ace with a couple of small mods I have it set up to perfection, pretty much never miss a shift, its super quick and quiet... but I have decided to try Dura Ace 9150 and see for myself..!

[@user-cx2bk6pm2f]

Global Cycling Network written in binary.. nice 👍 The heavy lifting of coding, though, is done in hexadecimal.. which is even cooler than binary!

[@dpw6900]

Mechanical until it trickles down to 105

[@brendangray]

Can I ask? . Do you mean get mechanical unless you are getting a groupset above 105? Thanks 🙏

[@ritzk79]

@@brendangray meaning mechanical until we get 105 di2

[@morgandebruler9281]

@@brendangray basically anything above 105 is very expensive (and in my opinion unnecessary) but the tech tends to 'trickle' down so in about 5 years you'll see Di2 on more affordable groupsets

[@jamestravill9640]

@@morgandebruler9281 took 10 months..

[@pedrolahoz]

Love my ultegra rx di2. Love it

[@mistagregory]

Ultegra/XT Di2 on my OPEN U.P. and mechanical Campagnolo Athena on my Pegoretti Luigino.

[@longerranger]

Di2 will also help in running much easier gears for long climbs. I live in the heart of the Alps and run a 10/42 rear cassette with 50/33 up front (11/42 with 50/34 is great too). The Di2 default means you can’t use the 2 smallest rear cogs when in the smaller front chainring, and so chain slack is not an issue. You do need a hanger extender and a medium cage rear derailleur combination as well : kzbin.info/www/bejne/eHTHZGV3grWDbrs

[@rzeckner]

I've had Ultegra Di2 for almost 6 years now and purchased it as a luxury item. However, because of its flawless performance without constant fiddling, it has now become a staple ensuring me of enjoyable ride every time and I won't purchase another bike without it. Nevertheless, I am unlikely to upgrade another bike that is dedicated to my Kickr from mechanical to Di2 any time soon.

[@adamsteineke4661]

I splurged on di2 last year and am VERY happy with it.

[@bill_automated1226]

Insightful video. Thank you. I had no idea that the Di2 group set used the CAN protocol. Makes sense, but so interesting that a bicycle uses the same protocol as an auto! I love technology,

[@throx]

As far as I recall, the shifter signal goes to the battery, which processes it and then sends out a different "shift rear down" signal. That's how you get multi shift and other fancy stuff.

[@izi941]

In first gen (7970), the CPU was in the front derailleur, all newer have it in the RD 👍 battery can also be 3rd party (like with e-bikes: Shimano, BMZ or Bosch made batteries)

[@mindofmission]

Mechanical currently, 1X. Cannondale SISL2 50/34 compact crankset, Ultegra SS RD & 11-34 cassette.

[@cannongavinjr7166]

i use mech and Di2 love both ways of shifting!

[@davidmulligan42]

I have Di2 on my older bike, and love it. I went with SRAM eTap AXS on my new bike, and I prefer it to Di2 in the winter months. Even with heavy gloves you can't mess up an eTap shift.

[@MrBJPitt]

With newer di2 using full syncro you can also make both the left shifter buttons go up the cassette and right buttons go down the cassette or vice versa.

[@davidmulligan42]

@@MrBJPitt Interesting, I didn't know that. My Di2 is from 2014, and I never bothered adding the Bluetooth module. I did upgrade the shifters last year when my old ones were almost at end of life.

[@MrBJPitt]

@@davidmulligan42 you don't need the Bluetooth module. Just plug the charging cable into a laptop. But you do need the new battery to get full syncro shifting, as the brain is in the battery.

[@josephphillips865]

@@MrBJPitt Yep, just have to download the Windows e-Tube application and connect. A lot of people aren't even aware of this it seems.

[@davidmulligan42]

@@MrBJPitt Ah, ok. I have the older battery, and the new BT-DN110 one is $160. I'll wait until I need a new battery. I have 30,000 miles on this one, and it's still fine.

[@BetterShifting]

Cables being interchangeable is pretty obvious.. there's such a huge range of bike sizes and cable routing differences depending on the bike type. What is much more interesting (and useful to know) is that you can connect any component to any other component. There is NO 'correct' order or mandatory routing layout. You could connect the battery to one shifter, connect the rear derailleur to the other and it would still work (assuming you put a junction A in there somewhere). Strange? Sure - but it'll work. ;-)

[@chrisj5443]

I've just been using your website info on seatpost battery install as reference as I move Di2 battery to a new seatpost on my Specialized Roubaix. The Di2 came with the bike, and so would have been factory installed. The holder they used was different than any of the ones you show. It's a ribbed rubber style, but is a plug clipped onto the back end of the battery, plus a separate rubber doughnut-plug on the cable end. after some head-scratching, I made an L-shaped tool out of a piece of coat hanger, held the L in the radial recess near the front end of the battery, and was able to pull the battery out. I think I'll get one of the 2-piece front end holders (Ritchey) to install in the new seatpost.

[@BetterShifting]

@@chrisj5443 interesting! Some manufacturers have their own, yeah.. I also know a few people that had battery holders 3d printed to fit their weird seatpost shapes :)

[@funkycoldm3dina]

that sound @4:10 of the front derailleur is so awesome. something very robotically beautiful is sounds.

[@scotthamilton1054]

Great clear explanation. Nice vid.

[@martynstokes9289]

di 2 the way forward

[@fernandoespinosa3403]

I’m too old for that when the traditional system has worked flawlessly forever for me.

[@Horstelin]

Until you have 100% integrated cables... The question is of course if you really need them

[@J88HNT]

I have both SRAM AXS ETAP and Shimano Ultegra mechanical. I changed the gear cables recently for new ones on the Ultegra set up and the shifting quality is buttery smooth. There is something just a little bit nicer when changing with mechanical gears. I feel more connected to the bike.

[@josephphillips865]

@@J88HNT That's one reason why I'm sticking with the mechanical Dura Ace groupset on my road bike. The downside is spending money and time replacing cables and housings with routine maintenance unless you happen to find that job therapeutic. I like the tactile feel and sound compared with a dull electronic button to shift. I did however splurge by getting GRX DI2 for my new gravel bike build. I do like the low maintenance aspect and features of DI2. It was a bit of a pain dealing with wires but now that it's setup it just works.

[@timothymatthews4399]

I have a shimano Alfine 8 IGH. Is it possible to add on to this a Di2 shift system or do I have to buy a purpose built Alfine8 Di2?

[@gsmd770]

I use the Ultegra Di2 system on both my bikes.

[@neil7769]

It's really fascinating to see all of the comments lamenting that Di2 isn't wireless.. Why? Apart from the initial hassle of installation, there are really no downsides to a wired shifting system, and it avoids the hassles of having to charge multiple batteries and potential pairing/connection issues. The wires are internal after all. It's fascinating because it must be more of a cultural rather than a practical preference. I hope that the manufacturers don't give in to this pressure and burden us all with daily hassles of unnecessary wireless complications.

[@virtualmartijn]

The other advantage of going wireless (at least how SRAM does it) over Di2 is that when a battery dies you'll still be able to swap it out with the other one so you at least have shifting at the rear derailleur. If your Di2 battery dies, you're hosed.

[@neil7769]

@@virtualmartijn Except it never happens.. I have EPS rather than Di2 but with that at least, you get weeks of warning when your battery needs charging. You'd need to have a fault with the battery or the connections (or just be very careless) to ever have the battery die during a ride. In this case at least, I think the drive towards wireless has more to do with trends and perception (it's a more modern solution) than practicality. It's like using WiFi rather than a wired ethernet cable for a static desktop PC where you have easy access to a socket. Why introduce unnecessary instability? However, a major advantage of wireless is ease of installation - and that by itself could be a good enough reason for using it. I build all my own bikes and it's always the cabling and/or wiring that involves all of the time and hassle. I recently had to resinstall my EPS system on a frame that already had the BB and BB protective sleeve fitted, and it literally took hours to feed the cables past the BB... At that moment I'd have given anything to be able to just bolt the stuff on and have it work immediately.. :-)

[@SxWerks]

You just convinced me that wireless is the way to go.

[@DanRC69]

A shame it's not FULLY wireless, as it just looks too messy and cluttered on a bike.

[@trepidati0n533]

You don't see the cables on a bike though. They are routed internally. Regardless, wireless isn't all it is cracked up to be. I have seen SRAM systems flakeout in high wireless environments. Don't get me wrong...wireless is great....when it works. :)

[@omurize2007]

Fully wireless is good.....until you have to charge all of those devices separately and the connection suddenly drops in an area with high interference and you get forced into the wrong gear at the wrong time

[@petinka721]

Would it work better for Ollie if he had sprint button for perfect gear for keep it up and not be dr*pp*d again?

[@imaXkillXya]

Waiting in the tech to trickle down all the way to tourney DI2 or sora DI2.

[@bossg2817]

I'll wait for claris Di2

[@frankb.1284]

I know it works flawlessly, but a wired electronic groupset makes no sense to me in 2021.

[@BetterShifting]

Good thing they're announcing the new groupset soon then! (well, probably.. no one knows 100% sure ;))

[@bmmaia81]

respectfully disagree. At least until today, a wired system is faster than wirelless. Maybe this changes tomorrow, but not today. And in theory we can always think that a wireless system is more prone for interference (intentionally or not). Yes, this second point is a bit of a stretch, but...

[@bmmaia81]

2 batteries instead of one. More autonomie because wireless consumes more energy, etc.. So I wouldn't say it makes no sense. there are pros and cons.

[@downinla4076]

And how often do you change out your group set that wireless matters? Every other day?

[@fergusdenoon1255]

@@bmmaia81 doesn't that statement make a mochery of the claims that you only need to recharge it ever few months...

[@ulaev]

i know how its works. the bigger question is : how I can buy shimano gruopset in 2021? in all shops is OUT OF STOCK

[@Ryan97beyond]

my wallet decided it would be better to use mechanical shifting. 🤷🏻‍♂️

[@yoroshikune08]

Nice video.. Finally can see how it works. May I know what watch are you wearing? Thanks.

[@BrentonChan]

Di2 is still a pipe dream but I love my Ultegra mechanical.

[@OhShunz]

I’m considering an upgrade of my current Ultegra 11spd. Mech to the 11 spd di2 but thinking about the wireless 12spd seems like such a fun aspect.

[@vinceasmith]

interesting, did not realise it was Canbus. Also the same two-wire cables carry the power from the battery to the electrical motors in the derailleurs.

[@markmichalowski4822]

I'm sticking with the non DI2, DI2 is way above my budget. Great videos

[@trepidati0n533]

Buying them gently used is a great way to get it for a decent price. You can save 2/3rd's the cost by getting a 2 year old version.

[@markmichalowski4822]

@@trepidati0n533 I may have to look into that, Thanks

[@playandteach]

I hear from friends that it is a game changer, although I'm perfectly happy where I am. What I don't understand is why we are still using cables? Can't we move to bluetooth or Ant +?

[@adamsteineke4661]

Sram uses wireless, but that adds multiple batteries to the mix.

[@playandteach]

@@adamsteineke4661 That makes sense, though I'd rather have the batteries and no hassle of cable threading.

[@neil7769]

@@playandteach I'd rather have the one-off hassle of cable threading than the permanent hassle of multiple batteries and potential pairing issues.. Just like wired ethernet vs. WiFi, wires are best unless you have a good reason to ditch them!

[@omurize2007]

@@playandteach what's more hassle is having to remember to recharge multiple smaller batteries each time versus charging a single big battery, and the connection dropping randomly when there's high interference around which makes you unable to shift, plus as one of the comments said, how often do you change your entire groupset that having no cables does matter?

[@SkyhawkSteve]

as an electrical engineer, I've designed items that used CAN to communicate. These had separate wires for power, though. Does Shimano use a version where the data rides on top of the power, similar to "power over ethernet"? I've found a few mentions that there might be ways to do this, but it seems uncommon. This is a deeply techie question for GCN, so apologies in advance. ;-) For anyone wondering about CAN, here's the Wiki page: en.wikipedia.org/wiki/CAN_bus

[@SaschaN]

I think it's much safer to separate power and signal lines If you want a fail safe mode for your components, because if the signal and power is lost, nothing is controllable anymore. If your signals and power are splitted, your powered components are still able to go into a specific mode by themselves. But this is just important for critical components (I wouldn't say that shifting is a critical component, but maybe they will implement wireless braking in future?!).

[@virtualmartijn]

If there are two wires per cable then one is power and the other is data I would assume.

[@SkyhawkSteve]

@@virtualmartijn I think a ground wire is still needed to let those electrons get back to the battery, as well as being needed for the data.

[@p.a.ch.3861]

Always prefer mechanical group sets; a fan of Campagnolo mechanical sets

[@donball370]

Looking forward to Shimano's next generation Di2. Hopefully then onto a new bike, disc brakes and Di2. Will keep old bike, rim brakes and 105 manual, after all n+1 rules apply

[@elorz007]

Global cycling network written in binary code but with which encoding? I will assume it's UTF-8 and that makes me happier.

[@zerocooljpn]

it's ASCII, the most basic encoding for the English language in binary. But unicode is ascii backwards compatible, so you can say this is utf-8 as well.

[@WoolyChewbakker]

Perhaps Shimano can explain why you need a completely new derailleur when upgrading di2 from 11 speed to 12 speed?

[@Zohar-Modifier]

like PDK :)

[@andredevasconcelos7804]

You should actually use the other end of the tool to plug the cables in. The "fork" side is intended for disconnecting the cables.

[@jasonree]

Definitely interested, need to decide whether to switch or buy a new bike with!

[@Munt23]

N+1

[@SeanBlader]

How does it do power and digital signalling over the same wires? Also the cylindrical end of the tool is used for pushing the plugs in, and the sharp end is used for prying the plugs out.

[@razorree]

can you explain price of the battery ~150-200 eur?? (for 2 cells, worth few quid and housing....)

[@eugabi9640]

Wireless to expensive for me. I would like such a groupset, Maybe 105 di2

[@trepidati0n533]

If Shimano ever did that....it could be a coup on the electronic shifting market.

[@joshwilliams6849]

I have got a Di2 bike back last November and whilst it is undoubtedly better as an overall package compared to mechanical SRAM Red I had before there are certain shift types that I miss from Red - mainly going down the rear cassette the feel from the click from DoubleTap was so solid and engaging (and the shift so quick). I think Di2 shifts the front rings far better though (as it should). I am currently in the process of building back up a winter/gravel play about bike with the SRAM Red so will be able to ride them back to back - as the reason for new bike was my bike was written off in a meeting with a car.

[@mrcross5716]

Awesome video can you do a di2 installation from scratch please

[@covali69]

Maybe I wasn't listening carefully enough 😅 I am interested in knowing how the shifters themselves work. And for example how do they adjust to be correctly on the gear (eliminating the need to adjust cable tension). Don't mean to be rude but the cabling part is quite obvious to me. Juicy detail please 🤓

[@adamsteineke4661]

The servo moves a predetermined amount of space that is adjustable with the fine tuning features. Also, you can tell the system exactly what you're running for gears and it will even display on a head unit.

[@covali69]

@@adamsteineke4661 thanks very much, that describes is really well.