Technique

On test: Shimano Dura Ace Di2

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Parent Category: Technique

Category: Shimano

Published on Wednesday, 08 September 2010 06:22

Written by Luca Salvatelli

The Shimano shifter has several positive aspects, but also some negative aspect

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After the test of Shimano Dura Ace, now is the time of Di2 electronic model. The two groups share the crankset, brakes, chain and sprocket. Similar commands, which only differ in the two levers and derailleur shifter acting on the command that sends an impulse for changing the gear. The rear derailleur follows the structure of the traditional one, but can accommodate up to 27 sprockets, with a capacity of less then. Even the front derailleur has the same structure as the traditional one, the special is not only to the electro-assisted movement, that the cage moves automatically to report back to avoid contact with the chain. The battery pack mounts easily under the bottle cage, or under the bottom bracket, under the top tube of the rear or behind the saddle (in cycling time trial). Is guaranteed for a period of charging enough to travel over 300km and a battery life of over 20.000km.

The road test

Di2 Shimano group requires a slightly modified frame for the internal cable. For the rest there are no further care. Although some have indulged in the positioning of the battery, the best solution is the one under the bottle cage, because it is well protected from any accidental impacts with rocks or other incident which can happen when you want to do the alternative at all costs placing the battery under the bottom bracket or some where else. The battery is easy and quick, is still more work to do, especially needs to remember to recharge it when you want to do a lot of laps long. It's can not then use this group cycling or ultra cycling or randonnee, where the group would stop working too soon. Moving one appreciates the advantages of the Dura Ace as good ergonomic controls, braking and its modularity, the rigidity of the crank. All of which had already noted in previous tests of Dura Ace. This differs in Di2 gearshift that a short and easy hike sends the impetus for the passage of the report. The trip is limited and the pressure required modest. One advantage for those with small hands, but not only. A pity that there is no possibility of changing multiple reports at once. Excellent solution that automatically moves the derailleur to avoid contact with the chain. The rate of change of gear is good, fast enough, but far from what can a traditional exchange used by a good rider. One Sram Red is far faster and with a Campagnolo Super Record, has increased or decreased by three reports, with the Di2 are still the first. Behavior that does not bother the cyclists, but annoyed agonists and may be disadvantageous in certain situations to tender. Excellent, like the Dura Ace traditional precision in passes and their relationship quiet. Only in the change effort gets noisy, but this occurs with all groups.

The maintenance group Di2 is another obstacle. The mechanics available to a tester that identifies the faulty then is replaced, do not fix anything, but not replace, a limit also very expensive (think of the need to replace the rear derailleur). Even then to check the actual battery life in the long run. A manual transmission, well maintained, even after 10 years continues to do its job, here are many more unknowns: the duration of the battery, which could be reduced over time causing the owner to replace it, or duration of electric charge. So it is not a group for people wishing to buy a bike and keep it for life. Even more is the very high price to be a real obstacle and that in itself introduces Di2 group no improvement in overall performance of the bike, even being heavier than the opposite is true. Performance and reliability over time is no doubt, therefore, to invest the difference of price between this and Di2 and traditional Dura Ace, in better components, like wheels or more. The price of Di2 group is about 2499 Euro. The complexity of Di2 justifies the price, but for performance, weight and reliability over time the price is literally "crazy" because it can not go faster, maybe the opposite is true, it is also more than 1000 Euro above the cost top range of other groups.

Positive aspects

Innovative project
Build quality
Ergonomic controls
Accuracy and noise in the steps of relationship
Ease of Use
Braking
Rigidity and smoothness of the crank

Negative aspects

Cost
Weight
Complexity of maintenance
Maintenance costs
Impossible passages multi gear

To learn more:

Shimano
Website: www.shimano.com