DIY DI2 w/auto shifting
09-06-20, 09:58 AM
#1
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DIY DI2 w/auto shifting
The system consists of a hall effect sensor at the pedals to measure cadence, an Arduino controller, and a servo mechanism to replace the manual shifter. Everything is mounted in a small enclosure on the frame. The only way to get one is to build your own, so a forum is available for Shift4Me builders, where the BOM, instructions, code and other documentation is available for download. Most bikes should be easy to convert, and [Jan] invites builders to post their modifications and improvements.Since the only input is the cadence sensor, we wonder if the system will interfere more than help when the rider has to break cadence. It does however include allowance to hold on the current gear, or reset to a starting gear by pushing a button. One major downside is that you will be stuck in a single gear if the battery dies since the manual shifter is completely removed.
https://hackaday.com/2020/09/04/auto...cycle-shifter/
https://hackaday.com/2020/09/04/auto...cycle-shifter/
09-06-20, 03:14 PM
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Arduino is a little out of my league. The best I've done is attach a RaspberryPI to my garage door so I can open and close it with my phone.
Seems like there is/was a commercial device that would auto shift a Di2 system by reading a cadence sensor and a power meter.
Sounds like a fun project, though.
Seems like there is/was a commercial device that would auto shift a Di2 system by reading a cadence sensor and a power meter.
Sounds like a fun project, though.
09-06-20, 04:00 PM
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Cadance based shifting has been tried but never worked well. You really need to integrate a powermeter and cadence with some sort of algorithm based on variable rider preferences. I suppose someone has already tried the power meter and cadence approach along with other inputs, but I don't specifically remember seeing any thing on it though.
09-07-20, 10:58 AM
#6
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It seems to me we already have everything we need with a phone app and DI2 and firmware hack to accept gear changes.
12-20-22, 01:36 AM
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There are quite a lot of such projects, minus being "speed based". I don't really understand the charm of "auto shifting". There were such derailleurs ages ago, albeit being "mechanical", and never took much attention.
To move a rear derailleur electronically, servo is the easiest, but most insufficient method. You need to supply current to servo all the time, otherwise if will rotate under even a small force, causing unwanted shifts. A better design is a lead screw. I've seen those too, if I remember correctly, a Japanese guy at Youtube made it. Also, Campagnolo uses leadscrews instead of cheap plastic toy gears which SRAM and Shimano use...
To move a rear derailleur electronically, servo is the easiest, but most insufficient method. You need to supply current to servo all the time, otherwise if will rotate under even a small force, causing unwanted shifts. A better design is a lead screw. I've seen those too, if I remember correctly, a Japanese guy at Youtube made it. Also, Campagnolo uses leadscrews instead of cheap plastic toy gears which SRAM and Shimano use...
12-20-22, 11:19 AM
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Dredging up old conversations isn't a great way to introduce yourself to the others here.
Welcome to BF.
Welcome to BF.
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12-20-22, 11:57 AM
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I enjoy seeing what creative people come up with, but about the last thing I would want is to have my bike shift based on cadence.
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12-20-22, 01:28 PM
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Riding a tandem with the drill instructor barking in your ear would get old quick.
12-25-22, 07:55 AM
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Your title is a bit misleading, as this gizmo really has nothing to do with Di2. It still uses a cable operated RD with servo operation vs. manual shifter.
If you really wanted to automate, the Arduino would send the proper signals to Di2 RD and FD, telling them to shift to a proper gear to maintain a set cadence. To me, it's a cool project, but really more of a solution looking for a problem.
If you really wanted to automate, the Arduino would send the proper signals to Di2 RD and FD, telling them to shift to a proper gear to maintain a set cadence. To me, it's a cool project, but really more of a solution looking for a problem.
