Short answer: no; it's either one or the other.

Longer answer: full synchro mostly includes all of what semi-synchro does. That is, when the system, while in full synchro, decides to shift up front it will offset at the rear the same way that semi-synchro does. In addition, while in full synchro you are free to shift the FD manually on your own, whenever you wish. The one thing "missing" from full synchro is that when you shift the FD on your own while in full, there is no offset at the back.

 

Short answer: no; it's either one or the other.

Ok, thanks for the direct answer. That's unfortunate.

Longer answer: full synchro mostly includes all of what semi-synchro does. That is, when the system, while in full synchro, decides to shift up front it will offset at the rear the same way that semi-synchro does. In addition, while in full synchro you are free to shift the FD manually on your own, whenever you wish. The one thing "missing" from full synchro is that when you shift the FD on your own while in full, there is no offset at the back.

I see them as very different concepts. One moderates the jump in gear ratio when you manually shift the FD, and the other lets you avoid cross chaining and makes it possible to use the right shifter to access your entire gear ratio range without using the left shifter. It should be feasible to integrate the two. However, given that Shimano has dictated it otherwise and I don't have the resources to hack the logic to do something else, it is what it is.

 

I'm actually not that clear on how useful semi mode is in use. I understand that when you manually shift the FD the system figures out where you were in terms of gear inches, (or whatever) and moves the RD to the next "harder" gear. I think.

Full Syncro makes sense especially if you set it up to the desired shift points. Thus if you are in the small ring and running down the cogset (11-23 in this case), rather then use the 11 after the 12, you set it up to go big ring and up to the 17 cog. Or wherever you set it. Or you stay in the big ring to the 21 cog, then the next shift to an "easier " cog goes small ring and R down to the 14. That makes sense to me and thus full essentially means you don't "need" the left shifter.

 

I'm actually not that clear on how useful semi mode is in function I understand that when you manually shift the FD the system figures out where you were in terms of gear inches, (or whatever) and moves the RD to the next "harder" gear. I think.

Semi-synchro is NOT that smart. It's not doing any sort of calculations. The "semi-synchro" mode is really just one function: whenever the rider manually shifts the FD, the system automatically moves the RD the other direction (as an offset) by 1–3 cogs. The amount the RD moves is chosen in the settings.

But this means the overall effect on gearing will depend on both how many cogs the person chooses in settings for the RD offset and when the rider shifts. For example, if you shift to the big ring while still in a relatively large cog in back and you have the offset set at 3, then this is going to be very different than if you are in the middle of the cassette with the offset at 1.

 

Is anybody running an 8050 or equiv. DA group and funding the 2nd smallest cog is locked out, regardless of Gear Position Control being set to off ?.

 

There are options but the system will only let you shift to the next available combination when moving up or down. There are limits as described here:

"To ensure rider comfort when using Synchronized shift, the cells may only be moved within aset range, which is established according to the following rules.

Synchronized shifting outward
‧ Synchro shift point RD gear position ≧ Shift end point RD gear position
‧ Settable range for the Shift end point shall extend to the gear position with a gear
ratio one step lower than that of the Synchro shift point.

(Example) If the Synchro shift point is 2.40, the Shift end point can be moved down to
the gear position with the gear ratio 2.26.

Synchronized shifting inward
‧ Synchro shift point RD gear position ≦ Shift end point RD gear position
‧ Settable range for the Shift end point shall extend to the gear position with a gear
ratio one step higher than that of the Synchro shift point.

(Example) If the Synchro shift point is 2.08, the Shift end point can be moved up to the
gear position with the gear ratio 2.12."

The system in theory allows a maximum cog move of 6 cogs, but only 4 in semi mode. I'm not sure if that means you can configure a move from a 34/12 to a 50/17, as I would be when using a 34/50 and 11-23. That would be a great automatic move. Likewise I'd love to use a 50/21 to a 34/15 which is the next logical move if doing it manually.

Time will tell if the system allows it.

 

The system in theory allows a maximum cog move of 6 cogs, but only 4 in semi mode. I'm not sure if that means you can configure a move from a 34/12 to a 50/17, as I would be when using a 34/50 and 11-23. That would be a great automatic move. Likewise I'd love to use a 50/21 to a 34/15 which is the next logical move if doing it manually.

Time will tell if the system allows it.

That's essentially what I'm doing on mine. You should have no trouble.

 

Please help me out with full synchro settings.

After a bit of a debacle, I've now updated the firmware on all my devices, precisely so I could check these setting, since Kestrel persuasively argued that it was do-able.

I can SELECT all sorts of gear points when creating a settings file, but the end result is always a file with an "!" icon added to it. And I'm unable to drag that file into one of the slots.

I've tried a dozen different arrangements, and the only ones it accepts are when the big to little FD shift point is chose at either the largest cog or the second to largest.

I'm making sure not to violate any other rules as specified by SteveB: my gear ratio jumps are small, etc.

I don't get it.

EDIT: Just to add, I've now confirmed this in the eTube setting on the Windows app. That app just lets you drag the FD down shift point with the cursor, but the ONLY options are 1st gear and 2nd gear (28 or 25); you can't drag it lower than that.

In the iOS eTube app I can choose those gears when creating a custom configuration, but it will not let me use that configuration.

I'm really at a loss as to how others are getting this to work.

 

In case it's not clear, here's what I'm talking about. The first image is the custom full synchro map I've created. It's simple, reasonable, and doesn't violate any Shimano rules. The second image is what you get when you save that map, and the ! means it can't be used.

I get the same results when using eTube on both iOS and Windows 10.
I have also tried saying I have a 53/39 or a 52/36 up front, and I've tried 11–32, 12–23 and everything in between at back.

No matter what I try there is one hard and fast rule: I cannot set a FD downshift that occurs in anything other than the largest or second-to-largest cog.

My only guesses now are:

1. Some people are using older firmware than I, and it's allowed for them but not for me?

2. Perhaps people are creating the setting file but not actually adding it?

 

No matter what I try there is one hard and fast rule: I cannot set a FD downshift that occurs in anything other than the largest or second-to-largest cog.

I see what you're saying. I just spent an hour trying to duplicate your intended map and couldn't make it work. My best guess is that's a bug in the software.

 

OK, in middle of an 8050 upgrade install and very frustrated.

1) The iPhone app seemed useless, then I downloaded the PC app and connected via the battery BCR2

Here's the issues:

- No ability to set to manual shift mode, synchro or semi seem to be it
- No 11-23 cassette option, in any crank type.
- No indication of battery charge on app's
- How to set to Gear Position Control adjustment ability for Do Not Set ?, this would let me manually use the 12 cog in manual mode, which I can not configure.

I mean is Shimano kidding ?, this is Nanny State BS

Unhappy with this

 

As to the first issue: there is nothing to 'set' in manual mode, so the app doesn't deal with that. The app configures settings for semi and full-synchro, and then when on the bike you use the junction box to toggle between the 3 modes. So this one isn't an oversight on Shimano's part.

As for all the other stuff: I can't help you there! Like you, I'm growing disappointed with Shimano's implementation of the di2 firmware and software interfaces.

 

OK, just read in the manual that Gear Position cannot be turned off if using a 34/50 crank.

Hmm.....

 

The conundrum of cheating the Di2 system.

1) Shimano has discontinued producing my favorite cassette, the 11-23 (they could not explain why), thus you have to cheat Di2 by telling it you are using a 12-25. Sucks as I like this cassette for flat Long Island riding as it has one tooth jumps from 11 to 19. It's still usable in Di2 (and available to buy), but see below.

2) If telling Di2 you have a 34/50 crank, the system will not allow access to the 2nd smallest cog, what Shimano calls the 10th cog. They state this is to prevent cross chaining, yet it's allowed on other cranks. They won't change this limitation. I asked.

3) The results of the above are that you also need to lie about the crank, a 36/52 will allow access to the 10th cog.

4) When viewing the cog/crank gear locations on a Garmin or whatever, the readout is incorrect as to the Gear Combo. When you are in a 34/12 it's actually saying 36/13. Makes the whole point of getting this readout on your computer somewhat useless. This is a nit-pick somewhat, until you recall what the system costs.

5) Shimano is truly being Big Brother with this and is yet again choosing what works for the masses and not allowing much in the way of customization.

 

The conundrum of cheating the Di2 system.

1) Shimano has discontinued producing my favorite cassette, the 11-23 (they could not explain why), thus you have to cheat Di2 by telling it you are using a 12-25. Sucks as I like this cassette for flat Long Island riding as it has one tooth jumps from 11 to 19. It's still usable in Di2 (and available to buy), but see below.

2) If telling Di2 you have a 34/50 crank, the system will not allow access to the 2nd smallest cog, what Shimano calls the 10th cog. They state this is to prevent cross chaining, yet it's allowed on other cranks. They won't change this limitation. I asked.

3) The results of the above are that you also need to lie about the crank, a 36/52 will allow access to the 10th cog.

4) When viewing the cog/crank gear locations on a Garmin or whatever, the readout is incorrect as to the Gear Combo. When you are in a 34/12 it's actually saying 36/13. Makes the whole point of getting this readout on your computer somewhat useless. This is a nit-pick somewhat, until you recall what the system costs.

5) Shimano is truly being Big Brother with this and is yet again choosing what works for the masses and not allowing much in the way of customization.

What is annoying about the Garmin readout...you can customise your gears in your Garmin itself and have them read correctly....BUT...it resets after every ride.


Also note that only the cog tooth count and ratio fields are effected....that cog position readouts still work fine.