gsa103

Right. The system will automatically shift the front and rear to smooth things out.
I was just saying that if you still wanted to pre-set the front chainring you could accomplish the same thing by over-shifting then coming back.

So for example:
shift +1: +1 RD
shift +2: +1 FD, -1 RD
shift -1: -1 RD
Shift -2: -2 RD

You've effectively shifted the front without changing your ratios. Now when you start upshifting, as you accelerate you would have a bunch of gears before another front shift.

The trick behind the sequential shifting is that the cross-over points are different going up or down, so that you're never stuck constantly shifting the FD as you go up and down a gear or two.

LastKraftWagen

My understanding is that, with the LCD display, you could simply hit a button and turn off the sequential shifts. I think one of the hassles would be programming in all the chainrings and cogs so the computer knows which shifts are sequential, and whether the computer actually accepts this reprogramming as so far I've only heard of one cassette option and a limited number of chainring combinations.

Otherwise Wayne, I would say just let the sequentials do their thing... If set up and working properly in a road configuration, the shifts are so fast and precise you probably wouldn't need to cross chain in anticipation of the next hill.

My two phennings.

Dean V

So in its intended mtb application it will be able to shift front and rear mechs simultaneously whilst racing over rough terrain and not drop the chain, miss a gear or anything else like that? Sounds impressive. Might also work well with a wide ratio cassette and 2 chainrings close in size to give the in between gears. The similar chainrings would also shift even better than those of a normal spread.

waynesulak

You bring up a very good point here. Will users be required to use Shimano blessed chainrings and cassettes or will the controller adapt to custom setups?

I think electronic shifting will really become the standard at all component levels as the sequential shifting is refined. Really a lot of appeal to sequential at the entry level bikes. The user doesn't have to understand shifting "high" gears and "low" gears just get on and ride. Fewer controls to understand and it fits well with people who have never driven a motorized vehicle without an automatic transmission.

For me I am more excited about the triple front ring capability.

LastKraftWagen

LBS and I discussed possibility of swapping FD cages, he thought it would be beyond his shop's capability.

Barrettscv 

Technical FAQ: Di2 XTR opens up gear options for road bikes - VeloNews.com

akexpress 

As much as one may not like shimano there is little dispute that Dura ace and Ultegra forged chainrings are the best shifting rings out there. If you want the systems to work well and ride instead of mess around with it use the shimano rings and cassettes. With the multitude of road and mtn variations it should be possible to get the combination you want.

LastKraftWagen

Rad the jut osted Zinn Velonewsartice, and Idont get his explanation as to why the ripple won't work. He's mentioned several times that the shiftersare justwiches,but then states that the front XTR triple won't work because there are no road DI shifterwith three positions??? And yet, the rear shifters work either a 10- or 11-spd because "they are just switches," and it's the RD that determines number of shifts.

Am I missing something?

And thank you to Zinn and the tandemer with the question...Hav tried several times with no sucss to get tanem specific question answered.

Barrettscv 

From reading the article, I understand that the left hand road Di shifters are set for two chainings. It would shift either up or down, but not down-down or up-up.

twocicle

Since it is the derailleurs that do the thinking and the levers are just "buttons", Zinn's answer that the left shifter does not have 2 clicks to handle a triple front seems "iffy". Current Di2 derailleurs keep track of their positions, not the shift levers. Based on that, one would assume we should be able to press the left road shift lever two times to move the XTR FD over two chainrings. Possibly an E-tube firmware update needed, but that should be all.

Equally odd is Zinn's proposition to use the XTR double cranks on a tandem - seemingly forgetting about the need for a timing ring on a crossover - or if you give him the benefit that he is thinking of same-side-drive(?)... doubt it :/

I would like to read direct responses from Wayne Stetina - Shimano. Apparently it is bad form to post Twitter addresses on this forum (ie: censored), so just do a Google search "Wayne Stetina".

merlinextraligh

Not exactly an elegant solution, but it looks like you could put the XTR shifter with a conventional brake lever and have thumbshifter buttons inside the brake lever for sort of a DIY integrated shifter.

Barrettscv 

Another barrier to using a left hand electronic shifter with a road triple crankset is that an electronic triple front road derailleur is not on the market. As Merlin said, a bike would need to use a XTR front derailleur, crankset and front shifter.

LastKraftWagen

But the road shifters can be reprogrammed left to right... i.e. be reprogrammed so the right controls the FD and the left the rear. The TT/tri shifters work the same way also being interchangeable left to right, so if the regular shifters didn't work these will. If you could get the sequential shifting working in a road set up, I imagine the sprint shifters would work as well. They are just switches, its the derailleurs that dictate the number of shifts.

Barrettscv 

The concept is very easy to understand. But a concept is a concept until someone builds it.

LastKraftWagen

Didn't see this updated here, but in a Zinn article around June 10ish (sorry, screen-reader won't let me jump back and forth) he mentioned that his original comment about the DI2 XTR triple wouldn't work with road shifters was a "brain fart" and at the time he was thinking mechanical shifters... A further email quoted from Shimano clarified that the FD will in fact work with road shifters but the road chainrings were outside of size spec for the XTR component.

Update:
Still can't put in the link, if you search it out this is buried in an article about biopace rings among other things...

"Dear Lennard,
When you say there are not enough clicks on a Di2 chainring lever to shift a triple, what does that mean? I’ve always assumed that Di2 levers have two buttons — up and down — and I got the impression the newest versions will just keep shifting until the derailleur runs out of gears. Is this not true?
— Steve
Dear Steve,
Yes, it’s true. That was a brain fart on my part. I was speaking as if it were a cable-shift lever.
You could run the XTR front derailleur on the XTR triple crank with an Ultegra Di2 or current Dura-Ace Di2 lever. Shimano has made it possible for some time to reprogram the levers so that the right lever shifts the front and the left lever shifts the rear. So obviously, there is no limit on how many gears it can shift other than what the derailleur is limited to.
Here’s an answer from a Shimano spokesman to the same thing:― Lennard "
Copied from a Velonews article.

twocicle

********************************************************
*** Important notes regarding usage of the 11 speed M9000 cassette ***
********************************************************

see: https://www.cxmagazine.com/shimano-xt...ible-questions

Apparently the 11spd, 11-40 M9000 cassette will fit on 10 speed hubs (or 11 speed hubs with a ring spacer)! As bizarre as it may be, Shimano made this cassette to be 10 speed hub compatible - for obvious reasons - adoption by ppl with 10 speed mtn bike wheels.

As far as 11 spd mechanical road shifters and derailleurs goes, you are stuck with using only the road components together. The m9000 derailleurs have a different cable pull which will not work correctly with road shifters.

twocicle

from Zinn and Shimano...

So Shimano is saying they won't support the mixing of Di2 Road and XTR because the FD "might" rub?? Sounds like a lazy cop out to me. Just make the stuff cross compatible and stop the BS.

waynesulak

I am just happy that they did make it possible to use road shifters work with mountain triple group. This is more than expected and FD cages can be adapted which gives hope. Electronic triple is very appealing. Maybe Shimano will offer a road triple FD in the near future.

Chris_W

I seriously doubt it, they don't even offer a mechanical triple FD in any of their new groups (7900, 9000, 6800, 5800) or a road triple crank.

twocicle

The mtn mechanical derailleurs were compatible only thru to 9 spd, then they proceeded to change the throw ratio on the DynaSys derailleurs which created incompatibility. It's like they have two disparate product groups that deliberately don't talk to each other, or they are competing for market share.

waynesulak

I agree it has been frustrating that Shimano discontinued road/mtn compatibility. That is why I am pleasantly surprised that the road electric levers will work at all with the mountain group. This is effectively a reversal back to the compatibility that existed at the nine speed level.

geoffs

I went to the Shimano product demo in Sydney last week and I had a ride of the XTR Di2 equipped mountain bike.
The linear shifting works brilliantly.
I am sure some clever machinist will work out how to modify the XTR front derailleur for a road triple

chojn1

With an eleven speed 11-40 cassette and a 39-52 front crankset, do you really need a triple? The current Ultegra/DA can even take a 38-53. The range is just as wide as any currently available mechanical triple and the stepping is very reasonable. I am not sure of the advantage of the triple over the weight saving and simplicity of a double.
CJ

waynesulak

It depends how you define "reasonable" Somewhat of a hot button issue on this forum. Much discussed but gearing is very personal and dependent on power, cadence desires, riding style and terrain ridden. For us we like a very close cassette with steps at below 13% between gears. This means a double does not allow us the range we need. Triple like range makes the steps too big. Others need less gearing range or can work with bigger steps. For them a double works well. My conclusion is that if a double will work for a team with Di2 then it is probably the best for the team with mechanical shifting as well.

Search the forum for many posts with gearing calculations and graphs.

Team Fab

such as K Edge?