Di2

Does anyone know if its
Does anyone know if its possible to use an old shifter dismantled so as to have just the small buttons, to use as a hacked climbing shifter? I’m on Ultegra 6770.

No, it would only be of use
No, it would only be of use to have them as extra buttons, I spend 70+% of my time on the hoods tbh.

Some useful information in
Some useful information in those links, I hadn’t clocked that the sprint and climbers shifters were different things.

I’ve got the hydraulic ST785 STIs so sprint shifters are an immediate no-no (they miss the connection). It seems I’d need to buy a 5-port dura-ace junction box to get the extra port for the climber shifters (have the 3 port ultegra one atm), which turns it from a relative cheap thing which I might do for giggles – to a much more expensive proposition.

Should be fine from what i’ve
Should be fine from what i’ve heard/seen, as they’re a shifter switch in their own right and not slaved to the STI like the sprinter shifters were e.g.

SW-R600 Climbing/PAVE Shifter.
This shifter is for road bikes and is mounted on the upper horizontal portion of the handlebar, or any other location comfortable for the rider. They can be used in addition to the Dual Control Brake Lever/Shifter, or can be used on their own by plugging directly into a SM-EW90-A 3-Port Junction or SM-EW90-B Dura-Ace 5-Port Junction.

Shimano Ultegra and Dura-Ace Di2 Electronic Shifting – Everything You Need to Know

That said, i’ve not tried it.

Don’t you just get a
Don’t you just get a different junction box to add shifters. My Ultegra Di2 came with a junction box with 3 plugs, but I see in the manual you can get them with 5, which I assumed was to add shifters.

If this is the case, you’d just plug the additional shifter into the empty ports.

That doesn’t answer your question at all, does it :))