for full disclosure, i've ridden bikes with di2 since 2010. i've converted all my road and cross bikes. i ride mechanical shifting for MTB (though that may change). i've worked with plenty of shimano, sram and campy systems.
Tom A. wrote:
Let's take a look at the purported benefits:
- Shift quality: IME, shifts with good mechanical setups are just as nice. It might take a
tiny bit more force and/or movement at the lever, but I actually prefer that tactile feedback.
i think the top-level groups from every manufacturer are amazing. shift quality when properly set up is great. there are a few scenarios where di2 absolutely shines. they may not apply to everyone or very often, but for some people it is important -- e.g., front shifts under load...esp if you have stiff chainrings. (no, i don't believe mortals lose power by not having stiff chainrings, but front shifts under load is one area where flexy chainrings get exposed.)
tactile feedback is lacking in shimano's road di2 -- but they have reportedly addressed this for their MTB di2. i haven't tried it yet.
i recently switched my wife's bike to di2. after she'd ridden it a bit, i came to realize that there were many rides prior where she simply accepted being in the wrong chainring because she didn't want to/couldn't easily shift back to the big ring. her hands are small and in order to shift to the big ring she'd nearly have to let go of the bar to get the shift to happen. in some scenarios this was terrifying for her.
di2 tends to be marketed toward experienced cyclists, but i can see a strong benefit for women and/or riders with smaller hands. while my wife is a recreational rider, in the first week that she had di2 we discovered several other women who are far more accomplished (e.g., one who rides mountains in europe for 3 weeks each year) who simply do not shift the front ring.
it was surprising to me.
Tom A. wrote:
- Front shifting and trim: I rarely, if ever, use the trim settings on my current FD setups, and I don't get rub, plus I make sure the FD is set up properly to avoid drops, so I'm not seeing the point there either.
depends on the group. some groups require it, others don't. some groups -- IME -- are pretty damn hard to set up so that there is no rub at all. 7900 springs to mind. should be a 1-time thing, but di2 makes it easier.
Tom A. wrote:
- Not having to adjust over time: "cable stretch" is a myth...it's really about housing compression/degradation over time (especially at ferrules), and I've found that using quality, solid housing (such as Nokon) basically eliminates that effect so that my mechanical setups are virtually "set up once and forget". Plus, see my earlier post about Di2 not being immune to getting knocked out of adjustment.
everything can go out of adjustment. i've set up di2 on a number of friends' bikes. there are plenty of smart people out there who can't figure out how a barrel adjuster works (turn it counterclockwise to add tension...), yet i see them easily grasp the concept of micro-adjusting di2. this is not why *i* would by a group set, but i do notice it.
Tom A. wrote:
- Multiple shift locations: OK...I can see that for TT/Tri use. Then again, I also have to question how often that would actually be used.
i basically never use shifting from the horns during a TT, but i train on my TT bike and find the ability to shift from multiple locations is something i use often, on every ride. i don't even live in an area with much traffic (i'd be on the horns even more if that were the case), but on MUPs, rests between intervals, stuff like that...i'm using it quite a bit. i don't have to choose between the ability to shift and the ability to brake.
i actually think TT/Tri bikes are one of the best applications of the technology. i do like multiple shift points on my road bike, too (sprint shifters). not a reason to buy di2, but a point in favor...for me.
Tom A. wrote:
- Better hand positioning for UCI TTs: Understood. Then again, that's more of a "UCI silly rule" issue than a technology issue.
well, the UCI rules finally removed the mechanical loophole.
Tom A. wrote:
Are mechanical systems
really so hard to get set up properly? Is a quality cable housing really such a difficult thing to pay for...especially compared to the incremental cost of electronic shifting? I'm not seeing that.
i see poorly set up mechanical systems all the time. i see stock housing used, which DOES settle in a bit. they don't know that compression-less housing exists. nokon doesn't come stock on most bikes (any?) -- and many people i interact with aren't inclined to change their own housing. they don't know what they don't know.
most folks do the bare minimum of maintenance. in my opinion, di2 benefits that user.
Tom A. wrote:
Like I said earlier, I've spent some quality time on Di2 bikes...and I've never gotten off the bike and just told myself "Shit...now I've got to go buy a new gruppo." I've had that experience with other sporting goods before after demoing them (e.g. skis, full suspension MTB, etc.) so it's not like I'm immune ;-)
it's a fair point. i think it is not a matter of "need" but "want." some want it, some don't. the sum of the small benefits -- for me -- makes me want it, and when i switch back to mechanical after using di2 for so long i miss it. i never *needed* a cell phone, either, but now i feel as if i do.
you are a more than competent mechanic, you surely love the technical aspects of bikes....it's not surprising that you would see the mechanical setup as "no big deal." i don't think this represents the majority of cyclists -- at least not the ones i see.
i'm glad that there are options for everyone. i personally don't know too many people who would NOT ride di2 if it were equally priced as a mechanical group. even your interbike example suggests this -- if it cost you nothing additional, it sounds like you probably would have been on it for your S5.
(interesting that you mention that S5 point. for one of my bikes, i occasionally set it up for a pure hill climb. di2 makes it easier for me to swap bars. i run one shifter and remove the rear brake. i never pulled all this stuff when i ran mechanical, but di2 opens up that option and makes it easy enough that i now do it.)