Shimano Ultegra Di2 Review

Among the things I got to spend some quality time with in California was Ultegra Di2.  The Domane we rode was equipped with Ultegra Di2, whereas the Madone we had was equipped with the latest version of Shimano’s mechanical Ultegra.

My previous 2 road bikes were both equipped with mechanical Ultegra, so I have a lot of experience with it.  When I built up my Madone 7, I built it up with SRAM Red Yaw (which I still believe has the best feel of any mechanical system on the market).  And I’ve spent thousands of miles on the hoods of the SRAM Rival on my Vaya.

Let me start by saying that I am not a fan of the mechanical Shimano hoods.  After a lot of miles on the Ridley and its predecessors, I’ve concluded that Shimano hoods are just not the most comfortable out there.  In my opinion, the most comfortable hoods are Campy Super Record, followed by Sram Red.  I was interested to see how the Ultegra Di2 hoods felt.

To my surprise, they are substantially different from the mechanical hoods.  They have a nice shape, adequately wide (but not too wide), and nicely shaped to fall easily to hand.  I have no complaints about the hoods.  When I’m riding, I often ride with my palm on the hoods, my ‘trigger’ finger on the brifter lever, my next 2 fingers between the bar and brifter, and my pinky finger behind the bar (particularly when descending or riding in a paceline).  That gives me easy access to the controls and a good grip on the bar.  The spread between the hoods/brifter/bar made it very easy for me to do my preferred control grip.

The braking action was identical to the mechanical–it feels like exactly the same ratio of effort/braking.

Shifting…that’s what you want to know about, right?  In a word: perfection.

I don’t know how much time Shimano spent working on the tactile feel of the buttons, but I couldn’t criticize a single thing about them.  They just feel perfect–they feel substantial, but they’re easy to press.  Perhaps most amazingly (and I don’t know how they do this), the feel of the buttons changes at the end of the cassette.  With mechanical, when you reach the end of the cassette, the shift levers will not go over all the way–they stop mid-throw to tell you that you’re out of gears.  With the Di2, the buttons act similarly–there is a change in feel to tell you that you’re out of gears.  Amazing.

If you’re dumping a bunch of gears, going from the big end of the cassette (slow) to the little end of the cassette (fast), I get the sense that mechanical can make the shifts faster.  I could be wrong, but that’s how it feels.  Going in the opposite direction, Di2 feels faster.  There isn’t enough of a difference in speed to be a real advantage or disadvantage to either system…but it was something I was wondering about, so I checked it out.

Here’s the amazing part of Di2: it…functions…perfectly…always.  I tried to screw it up.  I tried to just partially press the shift button.  I tried to shift under load, on a hill, with a hard effort underway.  I tried to cross-chain to an extreme extent.  I tried shifting without pedaling.  I tried shifting while spinning backwards.  I tried everything I could think of to screw it up…and couldn’t.  It shifted perfectly every time, no matter what, load or no load.

Di2 on the Domane made a lot of sense…it made that a bike that you could do some Loooooooong rides on.  Even when you’re tired, you can’t miss a shift.  Honestly, I cannot overstate how impressive the shift quality was–it was outstanding, and amazingly precise.

The other advantage of the Di2?  If if needs adjustment, all you have to do is press the little inline trim button by the brifter.  No stopping to turn the barrel adjuster.  No trying to remember which way to turn it.  No worrying about running out of adjustment or cable tension.  Just press the button.  Now, mechanical systems shouldn’t require much adjustment…once the cables stretch, how often do you really touch the shifting?  (Not very often).  But the simplicity of adjusting the Di2 is pretty great…and there is no accommodating cable stretch, because there are no cables to stretch.

So for purposes of shifting (the intended purpose of a drivetrain), the Di2 is pretty hard to beat.  If all else was equal, in my opinion, the Di2 is more consistent and precise in its shifting than any mechanical system I’ve ridden, SRAM Red included.  You can’t do a partial shift, or miss a shift.  Press the button, get a gear.  It’s that simple.  Let’s be clear: Di2 made shifts under conditions when any mechanical system would have had a problem.  I can say this with absolute confidence because I duplicated the conditions with the mechanical Ultegra and got partial/missed shifts, and because I’ve done the same with SRAM Red.  You just can’t fool the Di2.

Of course, all else is not equal.  Here are the concern areas I have:

Wiring: The wiring is ostensibly waterproof and from what I’ve read, pretty durable.  On bikes that are built for internal routing, the Di2 looks pretty eloquent (save for the big bulk of the front derailleur)…but on bikes not intended for internal routing, the wires strapped to a bike frame don’t look nearly as clean as cable runs, for some reason.  Maybe it just takes getting used to.

Electronics:  Yeah–I’ll admit it…I’m skeptical about long-term durability of the electronics.  In the first gravel metric, my Vaya was ridden in water over the BB, and was portaged across a stream that was chest-deep.  I don’t know if the Di2 will stand up to that kind of abuse.  Shimano seems to think that it is pretty durable, and I haven’t read of any systems frying yet…but to be honest, I have the concern in the back of my mind.

Battery:  The first Di2 batteries I was seeing were mounted to the bottom of the downtube.  Ugly.  On the Domane, the battery was mounted under the BB.  Unless you were looking, it was pretty well concealed (from the drive side, it was hidden by the chainrings, and from the non-drive side, it was pretty unobtrusive).  As the Di2 matures, there are far more installations that involve throwing the battery into the seat tube.  That seems like an ideal solution to me–if you can hide it, so much the better.  As far as battery life goes, every report I’ve read has said that battery life is amazingly good…so that doesn’t really seem to be an issue.  I have to charge my garmin and lights once a week.  If I have to charge the Di2 battery once every couple months, that isn’t a big deal.

Would I buy it?

Yes.  And No.

I would have no hesitation or reservation about buying and using Di2 on a bike, from a functionality perspective.  It works great.  I’d use it on the Madone without any concerns, based on how that bike is used.  But honestly, with Illinois riding, I’m not sure that Di2 would give me a huge advantage…we don’t have climbing, and there really isn’t much shifting under load.  SRAM Red has been pretty flawless for me, so I don’t think going to Di2 would result in a marked difference in bike performance.  So yes, I would (in theory), but no, I don’t see myself upgrading.  (The better reason to upgrade might be to go to 11 speed someday, but I’m not feeling as though I’m missing anything there yet, either).

The Vaya presents a more compelling case to try electronic.  The Vaya gets run in a lot more challenging conditions…mud, wet gravel, slush, crud, steep gravel rollers, etc.  Those conditions present more of a challenge to mechanical shifting, and the advantages of Di2’s consistency seem to be pretty well tailored to those conditions.  That said, these abusive conditions are also the conditions that are most likely to expose problems with an electronic drivetrain (e.g. what happens when the rear derailleur is completely submerged into water?)  Perhaps if Shimano gets to market with Di2 and hydraulic disc brakes, we will see.  That would be a combination that I think would be hard to beat on a bike like the Vaya, assuming that the durability is there.  (That said, I don’t know where the battery would go.  The Vaya has a 27.2 seatpost…I don’t think a battery is going in there).

I had anticipated trying Di2 on this trip and saying: “Meh, no big deal.”  That isn’t the case. It is a big deal.  The shift quality, the tactile feel, the ‘always perfect shifting’…they’re pretty great.  As bike integration improves, the disadvantages are being addressed one by one.  And as riders get more time on Di2, my concerns about reliability and durability are slowly going away.

The Di2 Domane was a pretty compelling argument for how technology is improving bikes at an exponential rate, right now.  Purists gonna hate, but both sets of technology just plain worked–and improved the ride experience.  That, in the end, is what I want my equipment to do.  Di2 is worth a look.