Di2 9070 problem

bernithebiker

Been asking questions of Pokerface who's been very helpful, but don't want to exhaust him!!

Just installed a full Di2 9070 to an Sworks Tarmac.

All seems to work fine in terms of shifting apart from this;

If in 1, 2, 3, 4, or 5 th gear and in small chainring, and decide to go to big chainring, I shift up, but about 3 to 4 seconds later, the front mech decides to shift back down again, to a kind of mid-position. Bizarre.

If in the big ring, and moving up the cassette from 11, 10, 9, etc. as soon as I get to 5, the front mech drops the chain to the small ring, again positioning itself in a mid (no-man's land) position, so there is chain rub.

Obviously, I would rather decide myself when to change big rings, rather than a computer!

Any ideas?!

bernithebiker

Spoken to Madison, doesn't look good.

They suggested a reset, which I did; chain goes through a full shifting pattern automatically, then stops.

After this, the problem is still there.

So either I plug it into a diagnostics box, or I may have to return the front mech.

Highly disappointing!

Manc33

I don't have any answers sorry but I wondered, are those Di2 mechs (accidentally) able to shift when the chain isn't moving? I mean can it go haywire and crunch your chain against your chainrings when its "setting up"?

ugo.santalucia

Manc33 wrote:

I don't have any answers sorry but I wondered, are those Di2 mechs (accidentally) able to shift when the chain isn't moving? I mean can it go haywire and crunch your chain against your chainrings when its "setting up"?

Manc33, I already warned you to stop trolling... if you have something sensible to add to the thread fine, otherwise refrain from posting...

ror3h

Sounds like the trim function on the front mech is out of alignment or something, weird. Have you tried plugging it into the di2 software and adjusting it? Are the limit screws properly adjusted on the front mech?

bernithebiker

ror3h wrote:

Sounds like the trim function on the front mech is out of alignment or something, weird. Have you tried plugging it into the di2 software and adjusting it? Are the limit screws properly adjusted on the front mech?

I don't have any software as I just got this lot, and I have a Mac….!

Madison says it needs to be plugged into the diagnostic tool.

So I've taken the whole bike into my LBS, who seem as surprised and confused by this as me.

All the limit screws are set OK. The shifting itself works fine, no chain rub, nice slick shifts.

When I described it to Madison they said, ah 'ghost shifting', so they obviously know about it.

Frankly I'm gutted, and I'm regretting dropping an extra £1000 over the mechanical 9000 on my SL4.

Bar Shaker

Bernie it sounds like the offset trim has not been set correctly. It sounds like the whole mech is too close to the seat tube. There are 3 adjustments that set up the front mech cage. Offset, verticality and yaw. The offset is the one right in the centre of the mech and a grub screw presses against the metal pâté that you fired to the seat tube.

Di2 'over shifts' on the front mech and then returns to the optimum position. Set the trim so that it is correct on the front mech once it has settled in what is presently no mans land, ie after it has moved back after 3 seconds (is it that long?). It does this to move past the large chain ring to pull the chain onto teeth and then settle back over it, once the chain is hooked on.

Once trimmed out correctly, it won't pull the chain onto the small ring when it auto trims as you go back up the cassette.

Hope that helps. Let us know how you get on.

Pokerface

Just had one more thought - have you tried adjusting the trim of the front mech via the junction box method? (As in put the bike into adjustment mode or whatever it's called, and then use the left shifter to adjust the trim - much like you would do with the rear mech and right hand shifter).

Might need a little tweak there to stop it from dropping out.

I've already suggested the main culprits - which are checking the alignment of the mech, and the hi/low positions which you say you've done.

The last thing I can suggest is to try and find a shop or person who has a spare front mech to plug in and see if the same thing happens. If it does - it's not the mech. If it doesn't it is the mech.

Pokerface

Could you describe in greater detail exactly what the front mech is doing as you shift across the block from biggest cog to smallest cog at the rear (with front in the big chainring)?

Assuming it is lined up correctly in big cog, small chainring...

So, as you shift down the block - does the front mech move/trim as you go (every 2-3 shifts I think)? Or does it just stay there until the chain eventually drops back down to the small chainring? Or at some point does it actually move across to the LEFT, pulling the chain to the small chainring?

(I'm also assuming your battery is properly charged as a low change might cause the front mech to default to the small chainring, but normal it won't shift back into the big ring again).

bernithebiker

Thanks for the ideas chaps!

I just collected the bike from the bike shop (they hadn't touched it yet) as a friend of a friend is a well connected Shimano person based in Rennes.

He's coming to see me (220km!) today at lunchtime, bringing computer, etc. to interrogate the system and maybe update it. He also has a spare front mech.

So will report back on that.

I'm going to video this phenomenon now, so you can see. Watch this space….

bernithebiker

Here's the vid;

https://www.youtube.com/watch?v=Rl0j4XYgmVs

Pokerface

Just watched the video again.

I would suggest setting the high limit further out. It looks like like when it auto-trims in the middle of the block it's just dropping the chain because the mech is too tight on the right side. Either that, or leave it middle of block (ensuring it's still in the big ring, and use the electronic trim on the front mech.

Fiddle with that and see if it makes any difference.

bernithebiker

OK, so the rep. has just been to my house.

The front mech is kaput.

Despite him updating the firmware and checking it all out on his PC, the front mech still shifts when it wants to, not when I want it to.

We tried it on his Di2 bike, it did the exact same thing.

We put his DA 9070 front mech on my bike, works fine.

He will now sort out an exchange for a new front mech which I will install when it arrives and give him his back.

Think the odds must have been thousands to one against me getting a dodgy one, but there it is….

Pokerface

Glad you got it sorted.

Curious - where did you get the mech from?

I've had a couple break straight out of the box, but it was the mounting bolt. not the electronics. I've had at least one front and one rear die from use though.

bernithebiker

Pokerface wrote:

Glad you got it sorted.

Curious - where did you get the mech from?

I've had a couple break straight out of the box, but it was the mounting bolt. not the electronics. I've had at least one front and one rear die from use though.

Yeah, me too, it's not nice not having a working bike! But now it's started to rain…..

It was a 'special' deal via a mate that manages a young semi-pro team in France. Didn't come from UK.

Bit of a confidence knock for it not to work straight out of the box. Can only hope long term reliability will be good…..

At least I managed to use his program to inverse the shifter buttons. Big paddle now 'pulls the cable' as it were. I found it was the wrong way round for my brain……

Bar Shaker

Glad it's sorted Berni.