Introducing Shimano 105 Di2: The Revolution in Cycling Performance
Get ready to elevate your cycling experience with Shimano 105 Di2, the cutting-edge electronic shifting system that takes precision and performance to a whole new level. Designed with uncompromising attention to detail, Shimano 105 Di2 provides seamless, effortless shifting that enhances your ride in ways you never thought possible.
Featuring advanced electronic technology, Shimano 105 Di2 delivers lightning-fast and accurate gear changes with just a simple push of a button. With every shift, you’ll experience a smooth and reliable transition, allowing you to maintain your momentum and focus on what truly matters—the thrill of the ride. Whether you’re conquering challenging climbs or sprinting towards the finish line, Shimano 105 Di2 empowers you to unleash your full potential.
Embrace the future of cycling performance with Shimano 105 Di2 and witness a new era of precision, efficiency, and control. Join the revolution and prepare to redefine your cycling journey like never before.
Technical characteristics and innovations
We already talk in his long and extended day about all the novelties that he presented Shimano 105 Di2but before getting to the primary objective of this Review – explain how it works on the road – it doesn’t hurt to remember some of its essential features.
First again Shimano has opted for a hybrid system where the cable only ‘appears’ to connect the battery stored in the seat tube and front and rear derailleurs, which according to the brand guarantees absolute reliability in all kinds of conditions. Its wireless nature refers to the way the signal we emit from the shifters reaches the derailleurs, without any kind of cable.
A system that, just as happens with Dura-Ace and Ultegra Di2can be customized through the application of Shimano E-Tube Projectwhich allows, for example, to modify the operating speed or the amount of changes or crown jump we want per pulse.
In this sense, two of the most interesting functions – already known for their application to the upper groups – are those of synchronized or semi-synchronized shifting: the first automatically selects the most efficient chainring in synchronization with the change of rear crowns that we have done . While the second automatically selects the rear derailleur position to obtain an optimal gear transition when we have changed from a large to a small chainring, or vice versa.
The system can also be linked with most cycling computers/GPS, incl Garmin or Wahooto control from here other parameters such as the state of the battery or visualize the development we carry at every moment.
The new DN300 battery, by the way, we haven’t said it, but it has the same design as those of Ultegra i Dura-Ace and it is also housed in the seat tube, although it could even be mounted inside some seat posts, due to its small size (only 52 grams of weight).
Bet on 12
The jump to 12 speeds is, on the other hand, the second major innovation it incorporates Shimano 105 Di2. This implies a smaller space between the crown and the crown of the cassette, as well as a smaller difference between the teeth between them, which translates directly into a more staggered and progressive change, with less ‘jumps’.
The crowns are constructed of steel, cassettes are also compatible with 11-speed Shimano hubsand are available in combinations of 11-34 (the one we tried) i 11-36making it clear from the start with these numbers what the ‘type’ user of the 105 Di2 would be.
Closely related to this new 12-speed cassette, we find a rear derailleur completely redesigned and that, like its older brothers Dura-Ace and Ultegranow also performs the functions of switchboard and system charging port, with LED indicators that indicate when the battery is at 100% with the characteristic blue color of Shimano. A full charge will take us between an hour and an hour and a half, for an approximate autonomy of 1,000 km.
Unlike the mechanical 105, available in short and medium cases, the rear derailleur of the 105 Di2 it only needs one measurement to cover the entire range of available developments (minimum 11 teeth, maximum 36). In addition, it incorporates technology Shadow Rd for a smoother and more precise operation, in all kinds of conditions and position of the chain.
As for the set of pedals/rodsmade in aluminum with the already known technology Hollowtech IIis available in combinations 50-34 i 52-36with connecting rod lengths of 160, 165, 170, 172.5 and 175 mm. In our case, the Trek Domane SL 6 came with 50-34 and 172.5mm cranks. And the truth is that the black anodized finish they added to this component, as well as the rear derailleur, seems quite a hit to us. Although for tastes, colors.
The front derailleur, on the other hand, has a lot of similarities with the Ultegra Di2, with the same automatic adjustment system, by virtue of the chain junction, to avoid chafing of the same. A chain that, in the case of the Shimano 105 Di2is the same as that of the group SLX of mountain bikewith technology Hyperglide+ for smoother changes, treatment SIL-TEC for greater durability and system Quick-Link for the replacement and extraction of links.
Before moving on to the braking section, it must be said that Shimano makes the same available to the 105 Di2 user pedalboard games -in thread or press fit version- than for Shimano Ultegra. In our case, the Trek Domane SL 6 it came mounted with a Practice T47 perfectly compatible threaded.
Ergonomics and braking
We come to one of the points where the new Shimano 105 Di2 has taken another big step over its mechanical version. First of all, for the substantial improvement of the ergonomics of the handles, which already happened in the last versions of Ultegra i Dura-Ace and that, as expected, the new one 105 he has inherited from his older brothers.
Handles use two internal type stacks CR1632, to which Shimano gives an estimated duration of up to 4 years. We can adjust the reach or distance of the lever from the handlebars, depending on the size of our hands, as well as change the function of the buttons to raise and lower the crowns, by virtue of our preferences. In addition, the force we have to do to brake is noticeably less than in the previous version.
This is mainly due to the improvements applied to the braking system, which now makes it quieter, more powerful and easier to maintain, thanks to its unidirectional bleeding system. The actuation of the brake of the 105 Di2 it includes a quick initial contact point, and a space between the pad and the rotor 10% wider that guarantees a very quiet operation, without unwanted friction. The brake calipers, with two pistons, are Flat Mount and enjoy a very contained size.
Yes, it’s true. Technology is not included Servo Wave of braking modulation, yes present a Dura-Ace i Ultegra Di2and inherited from the brakes GRX of gravelbut the improvement remains substantial over previous versions.
The disks, equipped with the technologies Ice Technologies (to reduce heat build-up in sustained use) i Center Lock (which facilitates the mounting and dismounting of discs), are available in sizes of 160/140 mm, with the 160 being the one chosen by Trek for this one Domane SL. Logically, next to the 140 mm, the most common size on the road.
The Shimano 105 Di2 in action
On the go, the first sensation that the Shimano 105 Di2 it is the comfort provided by the handles, of a significantly more compact size and which adapt more easily to different types of hands. Both supported in the typical roller position, at the top, and in a climbing attitude, standing on the pedals, the shape and feel of the rubber used, as well as its thickness, are simply perfect.
At the time of actuating the changes, each pulsation is effectively translated into a smooth, progressive and correct raising or lowering of crowns, or change of plates. I assure you that you need to ‘fine tune’ to differentiate, with your eyes closed, the operation of one Dura-Ace Di2 and the 105 Di2. Not to mention the differences with the Ultegra Di2, almost non-existent. In any case, we could say that the touch of the 105 Di2 it is a point more ‘dry’ than that of its older brothers, but the truth is that it is difficult to find the flaws.
Remember, we’re always talking about performance. The materials and therefore the final weight and price are different. The 105 Di2 it is built to last and last. Ultegra i Dura-Ace to offer maximum performance with minimum weight. But I insist; at the level of operation, the ‘reasonable semblance’ achieved by Shimano with this 105 Di2 respect to the superior groups is to take off the hat.
Returning to the operation of the handles, but now in their braking function, the 105 Di2 wins again wholeheartedly, with a smooth actuation that hardly requires – at most – two fingers to apply all the power that the system offers. And we can assure you it’s plenty, after putting it to the Review on steep descents with double-digit negative percentages and tight corners, where at no point did the brakes show any signs of fatigue or weakness.
The general operation of the transmission is, in short, very smooth and fluid, silent when pedaling and precise when shifting. And if we add to this a braking system, as we said, bombproof, we are facing one of the best works carried out by Shimano the last few years.
Conclusion about Shimano 105 Di2
At this point, the question must be asked Who is the Shimano 105 Di2 for? Well, above all, for all those cyclists who want to make the jump to electronics and the 12 speeds within the universe Shimanowithout having to make the significant outlay that already entails one Ultegra Di2.
In this sense, it must be remembered that their operation is practically identical, its weight is only 280 gr higher… but its price is noticeably lower: around 2,000 euros for the complete 105 Di2 kit compared to 2,900 for the Ultegra Di2. The final prices may vary depending on the market situation, the choice of some developments or others or the changes we need in the measurements of some components.
A price advantage, compared to Ultegra Di2which is much more palpable in the OEM market, that is, in bikes already assembled from the factory with Shimano 105 Di2.
Likewise, if we’re looking to change road bikes, and we’ve just used a group as -rightly- idolized as the Ultegra mechanic, maybe it’s a good time to lower our aspirations and attend to the real needs of the cycling we practice.
First of all, because the quality of operation achieved with the 105 Di2 making it, again, the perfect group for the vast majority of road cyclists, as it once was. Only those who pedal at the highest level of performance or are professionals will get the most out of the top groups of the Japanese firm. That said, everyone is free to spend their money on whatever product they want.
And secondly, because the general situation of the market has made it necessary to arrive at a mounted bicycle with transmission Ultegra Di2 is no longer possible for everyone. For those who can afford it, perfect. And for those who can’t -or don’t want to…- afford it, the Shimano 105 Di2 has arrived to occupy a place where, we are sure, with the passage of time, it will gain many followers. There are plenty of arguments.