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As the undisputed market leader, Shimano almost single-handedly determined the technical development of road bike components for decades. With Di2, the Japanese company launched the first electronic shifting system on the market. The current, fourth generation is the first with radio transmission and has been on the market the longest among the three competitors, having been launched in 2022. The unrivalled shifting behaviour still sets the standard in the current competition, even if the differences have become smaller. Another strength of the Japanese: efficient and sophisticated metalworking. Even on the most expensive version, there is little carbon, but the weight of the Dura-Ace is still competitive. The efficient production technology and identical wear parts for road bikes and mountain bikes are also reflected in the prices: the groupset and spare parts are 20 to 30 per cent cheaper than the competition.
The Dura-Ace drivetrain
Compared to the competition, the choice of gear ratios is comparatively small: The standard cassette with 11-30 teeth is extremely finely graduated, the second option is a mountain cassette with 11-34 teeth. This allows a maximum of a 1:1 ratio to be realised. In addition to the traditional compact crank with 50/34, there is also a sporty 52/36; professionals ride 54/40. Thanks to the larger initial sprocket (SRAM and Campagnolo start with ten instead of eleven teeth), the cassettes fit on the standard HG freehub and therefore also on older wheels; there are therefore no restrictions in the choice of wheels. There are no points of criticism during operation. The biggest plus points are the quiet running, very smooth shifting behaviour and not too expensive wearing parts.
Advantages and disadvantages
- Plus: Smooth running, perfect shifting behaviour, relatively inexpensive wearing parts
- Minus: Small selection of cassettes
The high-end gearstick from Shimano
Whilst other gearboxes always crackle, especially when shifting to smaller sprockets, Shimano's top groupset changes gears somewhat more quietly. The secret lies in the perfectly matched sprockets and chains that have been refined over decades. The front derailleur also works impressively quickly and precisely in all situations - it doesn't get any better than this. The gears can be adjusted simply and intuitively. You can easily assemble it without instructions, and fine-tuning the rear derailleur with the Shimano app is child's play. The central and wired battery, which powers the rear derailleur and front derailleur, is usually permanently installed in the frame - the bike must therefore always be brought close to a USB socket for charging via a magnetic cable.
Advantages and disadvantages
- Plus: Smooth gear changes, simple adjustment
- Minus: Non-removable battery, expensive power meter upgrade
Operation and ergonomics
The arrangement of the shift buttons behind the brake levers is based on Shimano's shifting logic of the mechanical systems: the front button changes to a larger sprocket or chainring, the rear button to a smaller one. Those who are still used to the mechanical Shimano levers will quickly get to grips with them. Alternatively, the buttons can be reprogrammed or an automatic mode can be set. The two shift buttons are more clearly demarcated and can be clearly felt even when wearing gloves. The slim grip body can be gripped well by both small and large hands, and the grip width can be adjusted. The front hump is angled slightly inwards and offers a good grip if you want to flatten out in the wind.
Advantages and disadvantages
- Plus: Comfortable handles, easily distinguishable switch buttons, additional buttons on the handle hump
- Minus: -
The Dura-Ace disc brakes
The Shimano disc responds sensitively and is easy to modulate. For light braking, it requires slightly more manual force than Campagnolo and SRAM. However, in an emergency, the Dura-Ace (and the slightly cheaper Ultegra) also provide plenty of braking power, as an integrated brake booster delivers more and more braking power with increasing lever travel. One weakness is the lightweight brake discs with an aluminium core. They are prone to squeaking noises in wet conditions. During heavy braking, they can then easily rub against the pads. Heavy athletes should opt for solid steel discs, as the sandwich construction is not completely stable.
Advantages and disadvantages
- Plus: Sensitive response behaviour, plenty of braking power during heavy braking
- Minus: Sensitive discs, squeaking in wet conditions
App & additional functions
The Shimano app is user-friendly and has a lot to offer: The shifters are quickly paired, the shifting can then be adjusted via smartphone, buttons can be reassigned or automatic shifting can be set. Additional buttons on the hump of the shifters can be assigned functions, for example for operating Garmin or Wahoo computers. The menu navigation is somewhat cumbersome in detail, but offers more customisation options than the competition. The optional power meter (approx. €1,000) is also managed here, but only the charge status and calibration. To manage recorded rides, Shimano offers an additional web application focussing on training control.
Advantages and disadvantages
- Plus: Many customisation options
- Minus: partly confusing menu
Jens Klötzer
Editor
