DA 9100 mechanical vs Ultegra Di2 R8000 - Build Advice

[eric01]

OP have you test ridden Di2? As many have stated, there are pros/cons but largely up to personal preference.

[SilentDrone]

OP have you test ridden Di2? As many have stated, there are pros/cons but largely up to personal preference.

I’ve never tried the Di2 for an extended ride. I’ve done a parking lot test but that’s not representative in my book.

I’m leaning towards the DA mechanical because it’s familiar, lighter and simpler. The comment above about electronic being anathema to what a bike is has some resonance also.

One additional factor that wasn’t discussed is how this is currently priced in the Project One program. Like I said, the DA mechanical/Ultegra Di2 are the same price. The jump to DA Di2 is a $3,300 up charge. Because the jump to DA Di2 is so steep I won’t do that; that makes no sense to me.


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[Imaking20]

I have to laugh because the same thing happened to me! The problem is that no one reads instructions manuals anymore. The Shimano instruction specifically tells you how to eliminate a loose connection. See the attached photo. This is the wrong way to install a wire. Shimano says you need to leave a little slack of wire just before it goes into the shifter. One day I was on a ride and hit a big pothole. All of a sudden I lost shifting on the RD. It turned out that the force of the impact cause the shifter to move 1-2mm, and that force was enough to pull the shifter away from the wire which was tightly taped to the handlebar. By leaving a little slack in the wire solved the problem for good. Unfortunately most Di2 bike are installed like the one shown in the photo.

I didn't use tape but I had this connection come undone twice on my maiden di2 bike. It was annoying enough to keep me away from di2 since.

9100 is outstanding. I don't believe electronic shifting adds anything to my enjoyment on the bike - if anything, it takes away thanks to the risk of wires coming unplugged and batteries dying.

If the bike was a Madone - I'd be looking at etap just because my brain doesn't like cables and aero bikes. But since it's not intended to be an all-out aero bike - I say the decision is that much easier to go 9100.

[pdlpsher1]

I don't believe electronic shifting adds anything to my enjoyment on the bike - if anything, it takes away thanks to the risk of wires coming unplugged and batteries dying.

I find it interesting that you are bringing fear into the discussion. If I were you I would seriously consider stop riding a bike immediately. There's a greater risk of you falling off the bike and seriously hurting yourself than having a Di2 wire come undone if you have properly followed installation instruction.

I have to admire the OP for posting a purchase decision question but unfortunately the answers that are posted here are useless. This is due to choice-supportive bias human behavior. In short, if you have bought something you will give biased opinions that support your decision, and that all other alternatives are sub-standard. I see this type of behavior all the time on this forum. Here's the wiki definition of choice-supportive bias behavior. Based on the comments you made here you definitely exhibit this behavior

In cognitive science, choice-supportive bias or post-purchase rationalization is the tendency to retroactively ascribe positive attributes to an option one has selected. It is a cognitive bias. For example, if a person chooses option A instead of option B, they are likely to ignore or downplay the faults of option A while amplifying those of option B. Conversely, they are also likely to notice and amplify the advantages of option A and not notice or de-emphasize those of option B.

What is remembered about a decision can be as important as the decision itself, especially in determining how much regret or satisfaction one experiences.[1] Research indicates that the process of making and remembering choices yields memories that tend to be distorted in predictable ways.[1] In cognitive science, one predictable way that memories of choice options are distorted is that positive aspects tend to be remembered as part of the chosen option, whether or not they originally were part of that option, and negative aspects tend to be remembered as part of rejected options.[1] Once an action has been taken, the ways in which we evaluate the effectiveness of what we did may be biased.[2] It is believed this may influence our future decision-making. These biases may be stored as memories, which are attributions that we make about our mental experiences based on their subjective qualities, our prior knowledge and beliefs, our motives and goals, and the social context. True and false memories arise by the same mechanism because when the brain processes and stores information, it cannot tell the difference from where they came from.[3]

[Imaking20]

Have you bumped your head?

[SilentDrone]

Di2 because the mechanical hydro levers are fat, ugly, and bulbous.

Good point. I went to the shop today to compare the hydro vs. non-hydro. Indeed, the 9100 levers are more bulbous. And while I think the non-hydro has a better look, I'm not dissuaded by the the hydro levers. They look fine. The bulb shape sort looks like the 7800 style I'm running now anyway, minus the cables jutting out of the side like a grasshopper's antennae.

[njyeti]

I have 4 bikes with Di2 and 2 mechanical so have significant experience with both. If you are racing- hands down I'd recommend di2 as you can quickly jump gears and also shift in sub-optimal conditions like under load. However, if just riding I think it's a wash. Pick whatever one you personally gravitate towards- can't go wrong.

[Delorre]

For a disc build, I would go with Di2. 2 reasons : much lighter and smaller (you have to verify for the latest generations...) shifters, and with a little care, cleaner cable routing. An Emonda disc f.ex with mechanical groupset is an horor regarding cable managment As others have said, you can Always upgrade your R8000 with some DA stuff if you really want to save some weight.

[clipsed]

After 5 years of racing and riding 15,000km+ per year, Nothing made my experience more enjoyable than switching from DA mech to DADi2.

Omg i could never go back now!

(i do love my PM as well however..)

[morganb]

I really like Di2 and end up gravitating to whatever bike I have it installed on (I've moved it from frame to frame). The new mech, and 9000 series for that matter are both fantastic, and I have them on my Ti do everything bike and my steel bike, but for a modern race bike Di2 makes more sense. I've changed the shift logic to be similar to eTap (big buttons shift rear derailleur, small shift front derailleur). With hydro I think it would be a no brainer since the hoods are so much smaller.

[Nefarious86]

DI2 with disc. Never replace an inner cable again and trouble free shifting in even the most filthy conditions. Charge it every 3 months and enjoy life.

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[morrisond]

If I recall correctly 8070 UDi2 Hydro Levers, Calipers, Hoses, wires, batteries and Discs are essentially the same weight as DA.

The only savings on DA Hydro Di2 are the Cranks, cassette, FD and RD. As all that weight is in the bottom of the bike - you really won't feel it. ( I think you feel it a lot more when it's on the bars, or things like heavy caliper brakes - you can feel the extra weight when throwing the bike around).

Crank Weight Difference - 65G
FD - 28G
RD - 38G
Cassette - 57G

Total 188 Grams all on the bottom half of the bike.

If you are going Hydro Di2 - it makes a lot of sense to go with Ultegra.

[SilentDrone]

Thanks, everyone. I’ve decide to go with the DA mechanical hydro 9120. What compels me is the fact that I’ve absolutely loved my 7800 group and I just don’t see (for me) the need for any of the techie goodness that Di2 offers.

Thanks again this was a really helpful discussion.





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[kofsw4]

If I recall correctly 8070 UDi2 Hydro Levers, Calipers, Hoses, wires, batteries and Discs are essentially the same weight as DA.

The only savings on DA Hydro Di2 are the Cranks, cassette, FD and RD. As all that weight is in the bottom of the bike - you really won't feel it. ( I think you feel it a lot more when it's on the bars, or things like heavy caliper brakes - you can feel the extra weight when throwing the bike around).

Crank Weight Difference - 65G
FD - 28G
RD - 38G
Cassette - 57G

Total 188 Grams all on the bottom half of the bike.

If you are going Hydro Di2 - it makes a lot of sense to go with Ultegra.

Not really relevant to the discussion any more but I think there was a mistake in the Shimano catalogue that was rectified recently. The R9170 shifters were listed as 360g, the same as the R8070s, but the DA ones are actually 40g lighter at 320g due to carbon levers rather than aluminium.

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[Cemicar]

I know the author was done with this thread, but still believe the thread title should have been "DA 9120 mechanical vs Ultegra Di2 R8070 - Build Advice". While 9100 vs 8050 might be no less fierce than 9120 vs 8070, it's a totally different competition.

If I recall correctly 8070 UDi2 Hydro Levers, Calipers, Hoses, wires, batteries and Discs are essentially the same weight as DA.

The only savings on DA Hydro Di2 are the Cranks, cassette, FD and RD. As all that weight is in the bottom of the bike - you really won't feel it. ( I think you feel it a lot more when it's on the bars, or things like heavy caliper brakes - you can feel the extra weight when throwing the bike around).

Besides levers which is already pointed out, DA and Ultegra have different claimed weights for calipers and discs. What you mean by "essentially the same weight"?