How does Shimano Di2 Actually Work?| Electronic Shifting 101

over the past month or so i've made quite a few videos featuring shimano's di2 group set and it got me thinking about just how impressive the group set is in terms of the way that it communicates between all the different parts now whilst most of you might have seen di2 in action have you ever wondered how it works exactly well in this video we're going to cover just that and explain how the di2 system [Music] works [Music] before we get going i want to know how many of you use di2 shifting on your bikes or stick to mechanical shifting so head over to the gcn app and vote on the poll do2 has been around for some time now although the early systems do communicate in a bit of a different way to what this current setup uses so for today i've got the current existing di2 group set to use but rumor has it there is a new dual erase group set somewhere around the corner so keep your eyes peeled for that too first off we're going to need to lay all of the components out on the workbench in the sequence that they would be on a bike which isn't too complicated and most of you will know what order to put these components out and today we're not focused on the brakes so i'm not going to be including those in the components when we lay them out but once we've got that all in place we can look to get it connected up and making sense from this pile of cables that we've got so let's get on with that first [Music] so we've got all our components laid out in the correct order and that wasn't too tricky but to make this a working functioning group set we're going to need to link it all together using our selection of cables and junction boxes and this is the point when it can seem a little bit confusing but fear not because it's not as confusing as you think many people will assume that each cable and connection is specific to the component that it's going to but that isn't the case and i've pointed that out in a previous video all of the cables are interchangeable the only difference between them is the length and that is dictated by the two components that it's trying to link together shimano have a specific tool to aid installation of these little plug connectors on your di2 system and it's this which is called the tl ew02 tool and it's quite a quirky looking tool but it makes life super easy clicking the plugs into place and when they're clicked in place they have a nice positive engagement so you know they're nice and secure so that's everything connected together and i've tied it up a little bit as well that you can see here like i've coiled the cables up so that it just doesn't look quite as confusing as it would have looked otherwise and it gives a nice clear simple layout so with the front of the bike here you've got your shifters your left and right shifters which are connected in single cable up to a junction box and this bot this would be mounted inside the stem on the bike that this has come off of then you've got a cable that runs down through by the head tube to our first junction box here and this is located on the down tube but it can be located in different positions on different bikes and then from the junction box we come back out we've got the cable coiled all the way up down to another junction box which would be sat down by the bottom bracket from this point here we've got a cable that runs down to our front derailleur and then from the same junction box we've got one cable that comes out and up to the seat post here which houses the battery and the battery can be housed in different locations but on this example we're using a seat post mounted battery and then back down from the same junction boxes located by the bottom bracket you've got another cable the last one which comes out the back of the bike and then loops to our rear derailleur and this is all plugged in and should be working correctly so i guess let's give a little test nice see the rear derailleur is working back down let's just test out the front one so we got we go shift into the big ring and shift back down so that's all working perfectly [Music] i've already said all of the cables are interchangeable on the di2 system but we need to understand how that is and in simple terms it's because all of the cables here only contain two wires inside of them and the plugs on the ends are all the same so the only difference is simply the length between the ends of the plugs which is pretty basic to work out and all you need to do is choose the cable length relative to the position you're going to use it so if within these cables there are only two wires to link up all of these different components parts and the buttons you might be wondering how on earth the relevant parts move when you push the right button and that is the slightly more complicated part and shimano use a high-tech communication protocol called a can bus network and can bus stands for controlled area network most people will have not heard of a can bus system before but having previously worked as a car mechanic it's a system that i am fairly familiar with because almost all cars use a can bus system to link all of their electronic components together can signals use a binary code to communicate through all this network of cables and units and a binary code consists of just two symbols a symbol one and a symbol zero and those are in a unique sequence to give a specific code to the button or action that's required binary code is the most basic way that a computer operates and you can convert text into binary code just how a computer would use it to communicate with the different sections inside it and here's an example of global cycling network written in binary code [Music] whilst that all might sound a little bit confusing when we apply all those principles to our byte components it makes a lot more sense so one button is identified with a specific binary code and as that travels through the network of components each unit will recognize it and decide if it has to perform a set action to give an example of this on our bikes as i press the shift button at the front of our bike a unique coded signal travels through the network of cables and goes to each individual component on the bike but crucially it's only the rear derailleur that recognizes that signal and then operates accordingly those are the basic principles that make the entire system work seamlessly and is a very effective and efficient method of communication as impressive and high-tech as all of this seems the can bus system was actually invented by bosch way back in 1980 and over the years it's developed and evolved into the robust communication system that it is today and you could go on forever talking to endless details about a can bus system but in terms of a bike that's as much detail that we need to go in to have an understanding of how it works so there you have it shimano's di2 system and the can bus system explained and i want to know are you interested in electronic shifting or are you going to stick with your mechanical gears let us know in the comments section down below i hope you enjoyed this video and i'm gonna have to build my bike back up soon so i can actually ride home see you later

pexels photo 7243049

You May Also Like