Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

I don't think that will look as clean and I'm fussy.

I might take the opportunity to swap my handlebars which need the hoses routing through anyway so not all is lost.

Yes

Any post-mortem on the cable? After splicing some of these, I'm actually a bit surprised they can die under normal conditions. Fatigue at the edge of the heatshrink?

It looked a bit tight at the shifter end. I will put more slack there next time.
Otherwise no signs of damage, no tight bends or kinks, nothing untoward but swapping a different cable in its place immediately fixes the problem.
If anyone wants the broken cable to use the connectors or anything, feel free

Did you try scrubbing out the connector itself with cotton tip and isopropyl?

Nope

Try it.

I bought an external battery mount to make a custom Di2 battery pack but the mount doesn't work with the rest of the components when supplied with 8.4V. So I guess I need to update it, but I don't want to buy the ridiculously expensive Shimano charger to plug it to the PC. Do I have another choice ? Is the charger only a charger or something more complex (eTube stuff) ?

The Di2 USB charger includes PC interface gubbins.

AFAIK you can't use the external battery mount with the newer versions of Junction A that include a charging/PC port - it'll simply refuse to function. Therefore you need the old Junction A that doesn't have a charging port (used to be <£10 on ebay).

If you still need to update firmware with this setup you need to buy/borrow the PCe1 e-tube interface (£££ and pretty rare, though a good LBS might have one).

Anyone know if there is somebody 3D printing the actuator arm for di2 front mechs? It seems like such a small part to trash a whole mech for.

I just saw online that there are multiple versions of the mount, the last one is compatible with the SM-EW90 junction box. I don't know which one I have, I'll see when I get home (fingers crossed).

The Di2 USB charger includes PC interface gubbins.

So my only other option is to borrow one .. Thanks!

Don't suppose anyone has a 6870 front mech lying around where it's broken but the actuator arm thing is not broken? I've got a functional mech with a small piece of broken metal and it seems a shame to leave it in the spares bin if I can find a replacement bit (obviously shimano don't sell them)

How complex is the piece ? If it's not too complex you could 3D model it and have it 3D printed very easily

Not that complicated.... apart from the 3D modelling and printing part

Take a look at Fusion 360, it's very user-friendly. JLCPCB offers metal 3D printing, you just have to give them a 3d file

I'll have a check tomorrow/wednesday. I feel like I do but not 100%>

Cheers

What's the functional difference between a standard SM-BCR2 internal battery charger for £70-£80, or THIS on Aliexpress for £20?

Am I risking the life of my wife and kids in a house sized firey death by using this for a couple of hours every 6 months?

There's a lot of electronics in the Shimano chargers. I doubt they'd put it in there for nothing.

Here's one I prepared earlier...

Figured as much. Just need to stop being so tight I guess.

Yep but also they still want £20 for some cheap shit that might fry your Di2?

It might be fine. As hippy's pointed out there's a lot of circuitry in the Shimano chargers which evidently aren't in that cable. However, the Shimano chargers for the internal batteries serve a dual purpose in that not only do they charge the system they also provide an interface between the Di2 system and the eTube PC software. It may be that the AliEx cable is perfectly sufficient for charging, but just lacks the interface components.

On the other hand, it might destroy your Di2 components and then burn your house down. Only one way to find out...

The battery charging and protection electronics are in the battery module so the fire risk is extremely low.

The Shimano adapter seems far bigger than necessary for its known function, especially if you don’t care about the PC interface. It just needs a low-ish current step up voltage converter and a chip to tell the system it’s present. That could easily fit in the oversized USB plug on the Ali Express cable.

That could

But does it? :)