Campag4life

I am the new kid on the block with Di2 8050 and wanted to poll the BF collective as more than a few of you own Di2 bikes and I am a late bloomer.

Since I hate formal polls and am more interested in your comments, for those that have gone to the dark side...of the three choices...Semi or Full Synchro vs. Manual shifting, which do you prefer and why?

Many thanks. I am considering giving full Synchro a try at some point.

TimothyH

Manual.

I tried synchro but it shifted the front while I was standing hard on the pedals. I can't have that. Too dangerous.

Now I keep it in manual mode and have complete control over what gear I'm in.


-Tim-

Marcus_Ti

Semi-synchro. The simultaneous gear dump is great for rolling hills.

Campag4life

Thanks a lot guys. I am kind of a control freak and so not sure if synchro, semi or full is in my long time future.

But question to you Tim. Whenever most...presuming most and not all shift be it manual or electronic shifting...Don't you let up on pedal pressure when you shift?
So me manual, semi or full synchro mode, standing on the pedals and shifting is a no no. I don't bang gears out of the saddle. Instead, when sprinting I try to pre select what gear I believe I will need to be in to sustain my full on sprint. Maybe I do and don't realize it. Never touch the big ring position when sprinting because I am in the big ring already. Maybe I do tune the RD when sprinting however and I could visualize a worse can if you select shorter gear inches where the big ring dumps to the small ring. That maybe a game changer and not in a good way.

Curious if you have a different view of this. And maybe, shifting the big ring in particular is the kiss of death out of the saddle...certainly if shifting in the direction of big to small incidentally due to being in full sychro which could cause a real problem...if you need shorter gear inches than you pre selected for your sprint.

tigat

Full synchro on the Domane. It's a one-handed set-up and only one lever is in play for me, so not much choice in the matter. The climbing button on the bar top works the same. It took some time to get used to (I started using it on the Emonda in 2017 while the Domane was still in development, knowing it was coming on the Domane), but now is very comfortable and predictable.

Full synchro with a twist on the Emonda. This is a frankenbike mashup of a SRAM hydro hood and brakes and di2 climbing buttons, deconstructed and built into a housing with up down buttons, which was then put into the SRAM hood. The buttons on the underside of the hood were always hooked up to the rear, and they now run full synchro. The thumb activated buttons on the inside of the hood still control the front with no synchro override. I like this best of all.

I've always been a gear planner for hills, since over the years, most of the set-ups I've had have made shifting the front on a climb less than optimal. The di2 stuff, and Trek's creative work on my set-ups cured that, but I still find planning useful.

TimothyH

I think the bold/red portion of your post is relevant. It has been a long time and memories of the exact gear selection are fuzzy at this point but I think this is what happened.

Yes, I let up when shifting, It is possible to do so when standing as well, by shifting weight slightly. Climbing too, even when sitting.

Getting smooth shifts in the rear however, doesn't mean there isn't any power to the pedals. One can let up just enough, briefly, to smooth out the shifts. There is still some power applied though.

The front shifted by itself when putting enough power to the pedals that it became a safety issue. Dropped the chain 2x in one ride. That was enough. I don't want to have to memorize shift patterns and anticipate when the front might shift. Full manual mode is for me. I've been in manual mode since 1977 so maybe I'm just a synchro shift Luddite.

Lots of people like it though. I've heard "I never have to think about it" more than once. It isn't going to cost anything to try.


-Tim-

Campag4life

Thanks a lot Tim. Makes a lot of sense. Inadvertent shifting from big ring to small ring in the heat the battle could be a game changer.
Will be interesting to hear what others say as well. As Marcus has chosen Semi...gear inch matching when 'deliberately shifting the front' maybe the safest method in particular if wanting to gear match when moving between the front two rings and riding aggressively.

2manybikes

I read here somewhere a rider had poor Di2 rear shifting, and the bike shop cleaned the derailleur, and it was fine. Pcad had to re boot one of his Di2 bikes. Then it was ok.

Campag4life

Clever stuff Tigat thanks.
If not too involved can you tell us how you have two different setups on the same bike..separated by shifters? Do you have two junction boxes on the same bike, each with independent rain that can be programmed differently, one for synchro and one for manual shifting? Trying to figure out how you accomplished having two sets of shifters set up to shift differently on the same bike.

Thanks

tigat

I wish I could. Before the new battery and synchro option was available, the buttons were pointed toward the front and rear, respectively. When I replaced the battery, updated the file, and set up synchro, I didn't change where they were pointed. The shifters that were pointed to the back (top bar climber and under the hood) are now full synchro. The one pointed to the front still works the front. I'm thinking if I added another climber to the Domane and pointed it to the front, I could get the same effect.

Steve B.

I tried full synchro when I was running an 11-23 cassette (which I've used for years, I live on flat Long Island). Then I found out the E-Tube software doesn't allow you to select that cassette, seems Shimano might discontinue ?. That meant I had to cheat the system, telling it I was on a 12-25 or some such. That then didn't read correctly on my Garmin, which tells me the actual gears I'm sitting in (50/15 as example). Seeing that on the Garmin is useful as I don't have to glance back at the cluster. As I am anally retentive, I needed it to be correct. As well, with a 34/50 crank, the Di2 system will not allow a shift down to the 11 or 12 tooth cogs with a bunch of different cassettes chosen, it locks out those cogs.

So I ran the gearing charts and realized I pretty much never used my 11, 12 or 13 when in the big ring, I just don't ride that fast and the hills round these parts are not steep or long, so I swapped to a junior 14-28 cassette. That meant I was now able to stay in the big ring pretty much all the time using everything from the 14 up to the 21 with one tooth jumps. I then turned off Syncro and can use the 50/23-25 & 28 and if needed when a hill gets steeper, go down to the small ring.

Only cost me a chunk of change to buy that cassette and I now have a few 11-23's sitting around doing nothing.

I do wish Shimano would simplify the system and just let you dial in the actual ring and cassettes you want to use, not limit you to only what they currently they sell or recommend. I understand they worry about warranty issues if you cannot figure out many chain links required for a particular R derailer, cassette and ring combo's. But in truth and if you are not desiring to see the correct data on a handlebar computer, you can tell the system "53/39 - 11-28" and than just run whatever in manual mode,.

jadocs

I have full synchro on right now and have not had any ill effects on my riding. So far I haven't had to give a thought to using the front derailleur. Every once and a while I'll hear a little "buzz" so I know the synchro is doing something, but it has always been seamless with no pause or perceived difference is my power to the pedals or cadence. A buddy of mine who is way more knowledgeable in this area than me said that he tried the default synchro mode and it did not work well for him, but there was a way to fine tune it to your liking. So he told me to ride it in the default synchro and see if it works out first. So far so good.

Slick Madone

I run it pretty much in Manual mode now......I like the Synchro mode, but I found it killed the battery much, much quicker.

NoWhammies

Manual. I have never tried the other modes. I keep telling myself that I'll give the modes a go, but by the time I'm done with my ride, have cleaned up my bike and am up taking a shower I always forget to change it up.

gmarsden

I wish there was an option for auto small ring to big ring shifting but having big ring to small ring manual.

jadocs

Really??? That's really weird, I wonder why that would be. You would think that there would be no effect. I've been riding the heck out of my new bike and it's still green when I check the battery.

Noctilux.95

Synchro-shifting was so cool on day one. Now, not so much.

Slick Madone

I'm hoping someone here can explain in more detail, but I found that to be true, at least on my S-Works.

jadocs

I'd be really interested in finding out myself. My reasoning is as follows. The Di2 knows what gear you are in regardless if synchro is on or in manual mode. All that's happening is the sychro shifting the front and rear.....unless one were consistently riding in the gear combo that is "on the fence" so to speak and results in a lot of automatic shifting?

rm -rf

Syncro didn't exist "back in the day, many (4) years ago..." I'm happy with manual shifting, along with the "shift 3 cogs" on a long press.

Maybe once or twice a ride, I'll end up cross chained, big-big or small-small (but small-small is rare, since the chain makes a ticking noise against the pickup pins on the big ring when on the smallest two cogs and the small ring.) I go to shift once more, and there's no more cogs, so I shift the front and do the long press 3 cog shift in the back. So the automatic full syncro would avoid that.

I also sometimes lose track of which ring I'm in, when riding at the overlap speeds, around 12-18 mph. So I shift the front, but it's already in that chainring. (That would cause a chainring shift on Sram, when is just a toggle to the other chainring.)

But correcting a wrong shift is fast and easy, so these minor confusions are quickly fixed.


I'd rather just shift the front myself, I might be cross chained just for a very brief time, and a front shift isn't necessary, since I'll be back in the middle of the cassette soon.

Shifting under load
I'll shift the rear under load with no drama. When standing on a steep hill, shifting to a larger cog, I do try to have a slight pause in the pedal pressure, but that's all. I don't try the front under a lot of load, but it would likely work okay.

I was on a group ride this summer. We turned a corner, and there was a short steep grade right there, only 30 feet high or so. All the Di2 riders were spinning up the hill, the mechanical riders were still in their higher gears, mashing up the grade. Di2 is fast!

rm -rf

14-28 cassette to a 14-32
I did the same thing, but merged the 14-28 with a 11-32 to make a 14-32.
14 15 16 17 18 19 20 22 25 28 32 (20-32 from the two carriers off the 11-32)
I want the very close 1-tooth shifts in the 50 chainring from about 17 mph to 24 mph, when I'm hanging onto the fast-for-me group rides. It's great for that. And I still have the 34f-32r low gear for the steeper climbs. This 14-32 stays on the bike most of the time.

The downsides:
The 50-14 tops out at about 29-30 mph, so I'm coasting on moderate to steep downhills. I switch back to 11-32 if the ride will have very long downhills where I'd like to at least soft pedal.
Since the cogs are so close in cadence, I need to shift 4 or 5 cogs in the back when I shift the front, but of course, that's fast and easy with Di2. It would be annoying with mechanical shifting, I think.
Shifting past the middle cog where the two different cassettes merge can be noisy and very slightly delayed at times, since the teeth patterns don't match up there.

Seattle Forrest

I use semi. So when I shift in the back it's like normal, but when I shift the front the back moves too. I almost always want to do it anyway (pair a front and rear shift) and the system just does it for the and smoother than I can.

Occasionally I only want the front to shift and think I'll turn it off, but I haven't yet.

Cyclist0108

Mine is manual. In fact, I have avoided firmware updates so that I can cross-chain if I feel like it.

Just call me a Di2 Luddite.

-- Ned

TimothyH

Manual mode (friction) should make a comeback.


-Tim-

Nachoman

I wouldn't mind trying out the synchro shifting.
Is it available on my 9070 system?