Homemade Di2 sprint/climbing shifters

Discuss light weight issues concerning road bikes & parts.
TheDoctor
Posts: 19
Joined: Sun Dec 17, 2017 9:56 pm

by TheDoctor

In its normal "unhacked" setup, pushing one of the buttons down will close the circuit by connecting the inner and outer part of the contact. One of the buttons shifts up, the other one down. In this hack what you're essentially doing is to move the button that makes the contact to somewhere else (and replace it with a small microswitch). So what you need for each of the two contacts, is a wire core going from the outer part of the contact to a pole of the microswitch, and a core from the other pole of the microswitch to the centre part of the contact.
Pushing the microswitch will then close the circuit and perform a switch (either up or down). Same for the other contact of course.

So I have one length of two-core wire for each of the two microswitches. Of each wire, one core is soldered to the centre of the contact, and one to the outside. On the other end, one core to each pole of the microswitch.

Hope this clarifies?
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thefuzzycow
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by thefuzzycow

TheDoctor wrote:
Mon Sep 17, 2018 4:53 pm
Hope this clarifies?
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Cw75lea
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Joined: Thu Nov 08, 2018 1:16 am

by Cw75lea

IrrelevantD wrote:
Mon Aug 20, 2018 6:59 pm

So the sprint shifters are just that, momentary button that just complets a circuit. HOWEVER, the sprint shifters can only work if plugged into compatible brake levers (9070, 6870 and 9150), they only serve one function and are not programable. The left button moves the RD left (bigger), the right button moves it right (smaller). The climbing switches used here can operate completely independent of brake levers and have the same programability. They are essentially the same as the two buttons on the levers, so you could use them with non-Shimano brake-only levers. Ive seen people do this with flat bar conversions and non-shimano hydraulic levers.

EDIT: I just read up a few posts and saw your mention of having 8050. Completely disregard everything I've said about cutting e-tube cables and making the sprint shifters because they won't work with the 8050. It only works with SW-R610 compatible levers.
Why do you say this won't work with the 8050's? The 8050's have a dedicated sprint shift or "dumb" switch port. I was thinking I would make my own shifters using cut etubes with 2 tactile switches on the left side of the bar (1 sprint button position and 1 near the stem as a climber) for down shifting the rear and, 2 tactile switches on the right side of the bar (1 sprint button position and 1 near the stem as a climber) for upshifting the rear. I don't care to have a button in either position to switch the front derailleur as most of the terrain I have I'm either 100% in the big ring or 100% in the small. As well if running synchronized shifting the front wouldn't be done manually anyway.

Carter

Cw75lea
Posts: 10
Joined: Thu Nov 08, 2018 1:16 am

by Cw75lea

CallumRD1 wrote:
Mon Apr 23, 2018 4:58 pm
The switches were installed with a dab of hot glue and the circuit board and wiring were hidden under the bar tape. It all appears to be working perfectly, the only (non) issue being that I had neglected to remember which switch was up and which was down before soldering, so I had the left and right hand switches backwards (i.e. left hand switches move the rear derailleur to a harder gear and vice versa). This was easily rectified in the etube app by switching the roles of the buttons. All told this implementation took about an hour at a desk and 15 minutes to install.


IMG_1261.jpg
IMG_1262.jpg


Edit: fixed typo
So the switches shown in both of these images you just hot glued directly to the bar and then wrapped over them?

CallumRD1
Posts: 132
Joined: Mon Apr 03, 2017 2:54 pm

by CallumRD1

Exactly. The hot glue works best if you put a small piece of hockey tape on the bar first. The glue sticks really well to the tape but not so well to the carbon bar itself.

Cw75lea
Posts: 10
Joined: Thu Nov 08, 2018 1:16 am

by Cw75lea

Awesome, thank you.

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IrrelevantD
Posts: 359
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by IrrelevantD

Cw75lea wrote:
Wed Nov 14, 2018 11:48 pm
IrrelevantD wrote:
Mon Aug 20, 2018 6:59 pm

So the sprint shifters are just that, momentary button that just complets a circuit. HOWEVER, the sprint shifters can only work if plugged into compatible brake levers (9070, 6870 and 9150), they only serve one function and are not programable. The left button moves the RD left (bigger), the right button moves it right (smaller). The climbing switches used here can operate completely independent of brake levers and have the same programability. They are essentially the same as the two buttons on the levers, so you could use them with non-Shimano brake-only levers. Ive seen people do this with flat bar conversions and non-shimano hydraulic levers.

EDIT: I just read up a few posts and saw your mention of having 8050. Completely disregard everything I've said about cutting e-tube cables and making the sprint shifters because they won't work with the 8050. It only works with SW-R610 compatible levers.
Why do you say this won't work with the 8050's? The 8050's have a dedicated sprint shift or "dumb" switch port. I was thinking I would make my own shifters using cut etubes with 2 tactile switches on the left side of the bar (1 sprint button position and 1 near the stem as a climber) for down shifting the rear and, 2 tactile switches on the right side of the bar (1 sprint button position and 1 near the stem as a climber) for upshifting the rear. I don't care to have a button in either position to switch the front derailleur as most of the terrain I have I'm either 100% in the big ring or 100% in the small. As well if running synchronized shifting the front wouldn't be done manually anyway.

Carter
late response, I've been traveling for work and haven't been watching the forums.

I had read somewhere that the new 8050 and 9150's got rid of the dumb port and that the old sprint buttons no longer worked on the newer generation brifters. If this is incorrect and it actually works, please let me know. I've been thinking about getting a pair of 8050s for my road bike and picking up some used parts to upgrade my CX bike to Di2 and using the 6870s there.
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