Why the double barreled MTB shifter?

[Veloo]

I picked up an old, steel Trek 820 for a friend.
The 7 speed shifter has this 2nd hole. I haven't opened it up to inspect yet.

Why would this be needed?

[cmbicycles]

Shimano used to have some shifters with external gear indicators, so maybe they are a leftover from that bad experiment. I dont recall them having any function whatsoever when I've taken covers off to clean and lube shifters.

[dddd]

Exactly, the ports were for Shimano's odd, cable/housing actuated "CI-Deck" spedometer-head gear indicators.

The indicators with their miniature cable/housing connection were not all that reliable, at least as found on the used bikes that I serviced.

The system is a rare find, and I wouldn't mind having it on one of my rides as an oddity. Readability of the gauge heads was excellent.
https://www.google.com/search?q=ci-d...DAKhTEGwDHrhhM

[rice rocket]

Haha, that's cool if they were reliable.

Funny how everyone scoffed at FlightDeck and other shifter mounted indicators, but when Di2 puts it on your GPS unit, it's cool again.

https://www.velominati.com/irreveren...ft-indicators/

[Veloo]

Wow, I've never seen these.
They look like something you'd find on Ali-Express.

Originally Posted by dddd

Exactly, the ports were for Shimano's odd, cable/housing actuated "CI-Deck" spedometer-head gear indicators.

The indicators with their miniature cable/housing connection were not all that reliable, at least as found on the used bikes that I serviced.

The system is a rare find, and I wouldn't mind having it on one of my rides as an oddity. Readability of the gauge heads was excellent.
https://www.google.com/search?q=ci-d...DAKhTEGwDHrhhM

[Ken Robb]

Originally Posted by rice rocket

Haha, that's cool if they were reliable.

Funny how everyone scoffed at FlightDeck and other shifter mounted indicators, but when Di2 puts it on your GPS unit, it's cool again.

https://www.velominati.com/irreveren...ft-indicators/

My 9 speed Ultegra Flitedeck triple still works like new. I hardly knew how to respond to the guy who posted that the system had a fatal flaw because it didn't display accurate rpm when a rider was coasting. That may have been a problem for him but I KNOW my rpm when I'm coasting.