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Re: DIY Ultegra Di2 TT [RoninSherpa] [ In reply to ]
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Pardon my ignorance regarding Di2, but can the dura ace time trial shifters be used with the ultegra group?
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Re: DIY Ultegra Di2 TT [lemond853] [ In reply to ]
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The electronics disassemble out of the sti without having to destroy anything. There was two torx screws and an e clip. I was trying to hint that one could easily add on remote shifters to ultegra di2 stis by splicing into the wires running from the x/y buttons up under the hoods. It might be tight but should work.
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Re: DIY Ultegra Di2 TT [DC Pattie] [ In reply to ]
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DC Pattie wrote:
That is totally awesome. I'm guessing you could also use your protocol for a MTN bike XTR version?

As long as there is room to tuck away the little modules and a place for a couple momentary switches, it would work
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Re: DIY Ultegra Di2 TT [locutus] [ In reply to ]
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This is bad ass.
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Re: DIY Ultegra Di2 TT [Aralo] [ In reply to ]
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Aralo wrote:
locutus wrote:
Ultegra di2 uses canbus protocol

Do you have the spec for the message that are used (and bus rate etc) or did you reverse engineer it? I'm very interested in more details about the electronics if you're willing to share. Cool project!

Sorry, this particular method didnt really involve reverse engineering anything. The exisiting electronics from the STIs were used and the shimano x/y buttons were swapped out for momentary spst switches. I did hook the system up to a scope when i bench tested everything and was able to see very rapid voltage spikes and drops which I am guessing is how everything communicates.
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Re: DIY Ultegra Di2 TT [styrrell] [ In reply to ]
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styrrell wrote:
I dont think they will care much. The shift buttons themselves are very cheap, but to get it to work you need to buy a $450 road shifter set.


The STIs can be found new for $340...probably cheaper used. Still some what spendy but a huge savings over dura ace di2 all together
Last edited by: locutus: Feb 1, 12 9:48
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Re: DIY Ultegra Di2 TT [AndyF] [ In reply to ]
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Totally unrelated, but why do people ask others to PM them, when they want to ask a question?

You have the question, you initiate the contact???
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Re: DIY Ultegra Di2 TT [nickwisconsin] [ In reply to ]
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No. Ultegra shifters can not be used with the Dura Ace system or vice versa. The electronics are set up differently.
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Re: DIY Ultegra Di2 TT [nickwisconsin] [ In reply to ]
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No those have different wiring and they don't have (or need) the electronic brain. The brains for DA are in the derailleurs and the buttons are dumb, but this requires more wires going from button to derailleur.

Styrrell
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Re: DIY Ultegra Di2 TT [locutus] [ In reply to ]
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Heres a few more pictures:

Side view:


Battery mount under seat. Leads are ran into a tiny hole into the seat post where the battery is housed.


Front:

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Re: DIY Ultegra Di2 TT [locutus] [ In reply to ]
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Did you make that behind the saddle bottle mount? It looks great!
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Re: DIY Ultegra Di2 TT [timskee] [ In reply to ]
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timskee wrote:
Did you make that behind the saddle bottle mount? It looks great!

Yes, home made with carbon fiber. Making flat things out of carbon was surprisingly easy.
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Re: DIY Ultegra Di2 TT [sentania] [ In reply to ]
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sentania wrote:
Totally unrelated, but why do people ask others to PM them, when they want to ask a question?
You have the question, you initiate the contact???

Suppose you see an interesting post and want to talk to that person. But they're not set up for PM. How would *you* solve that problem?

AndyF
bike geek
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Re: DIY Ultegra Di2 TT [AndyF] [ In reply to ]
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Locutus appears to receive personal messages.
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Re: DIY Ultegra Di2 TT [sentania] [ In reply to ]
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sentania wrote:
Locutus appears to receive personal messages.

I may have missed the PM button, I guess. I scanned for it initially, of course, but didn't see it. My apologies, sentania. I didn't mean to pollute the board.

AndyF
bike geek
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Re: DIY Ultegra Di2 TT [AndyF] [ In reply to ]
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Personally I don't care, I just have never understood why people always ask others to PM them.... with the acceptance of PMs indicating desire to be contact directly or not, combined with the presence of an email address providing a preferred means...

/shrug
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Re: DIY Ultegra Di2 TT [sentania] [ In reply to ]
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sentania wrote:
Personally I don't care, I just have never understood why people always ask others to PM them.... with the acceptance of PMs indicating desire to be contact directly or not, combined with the presence of an email address providing a preferred means...
/shrug

Got it. I just missed seeing the PM button this time. I had simply forgotten where it was.

Maybe, in a way, this also helps you understand why people do this. (If your browser is stretched out, the PM button is waaaaaaaay over in the bottom right, whereas all the other user info is located on the left side.

AndyF
bike geek
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Re: DIY Ultegra Di2 TT [AndyF] [ In reply to ]
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The color scheme on those buttons could use some work....
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Re: DIY Ultegra Di2 TT [locutus] [ In reply to ]
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Locutus,

Based on your tinkering, do you need to use a front derailluer with Ultegra? Could you run a single chainring with out using the front der?

What shimano parts did you buy?

It looks like you used the Cateye remote buttons, right?

Thanks for posting and putting up with all our questions.

Scott
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Re: DIY Ultegra Di2 TT [lemond853] [ In reply to ]
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Hello, I'll double check tonight but I'm fairly sure the front derailleur is not needed and you can run just the rear. The shimano parts I bought were the front and rear dérailleur, battery mount, shifters and front harness connecting the two shifters (this could be made but you would lose the ability to adjust the derailluers and the battery level function).

I ordered some small water proof spst momentary switches...they were only $1 ea. I didn't use the cat eyes because they are more of a surface mount switch.
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Re: DIY Ultegra Di2 TT [lemond853] [ In reply to ]
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lemond853 wrote:
Locutus,

Based on your tinkering, do you need to use a front derailluer with Ultegra? Could you run a single chainring with out using the front der?

Just checked...everything works fine with only the rear derailler and shifter so you could use a single chainring up front with no problem.
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Re: DIY Ultegra Di2 TT [locutus] [ In reply to ]
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locutus wrote:
Heres a few more pictures:

Side view:


Battery mount under seat. Leads are ran into a tiny hole into the seat post where the battery is housed.


Front:

just want to applaud your ingenuity, again, and say that's a nice looking setup! also, your homemade shifters are shorter than the shimano ones (da di2, at least....presumably shorter than the ulty TT shifters will be, too, whenever they appear). doesn't matter for tri purposes but could matter for TTs (UCI regs).
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Re: DIY Ultegra Di2 TT [locutus] [ In reply to ]
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Locutus,

Thanks for the thread. This has got me really interested in ultegra Di2.

So, while walking the dog in the snow this evening, I started wondering how I could do this with my TT bike. I am happy about putting two buttons on each of the aero bars but am not sure that I have space to make it easy to do with the bulhorns (I am not sure how long the internal bits of the brake levers are). This got me thinking along the following:

1. Why do I need two buttons for the front derailleur? One button by itself would be fine as all you need it to do is to move the other way (i.e. if it is on the big chain ring, it just needs to go down to the small one and vice versa). I didn't think any more about that though because...

2. Why can't I just get away with four buttons (one "up" on left aero and left bullhorn, and one "down" on each of the right ones)? Basically, why can't I sequentially shift up and down without having to think about whether I am moving the front or rear derailleur.

After I got to the sequential idea, I gave up on 1 as it sounded a lot better!

For the final year of my engineering degree (well over twenty years ago now) I built a boat about 1m long that had a tiny Z80 computer in there that took instructions from a PC on the shore (steer 270 degrees, "slow") and it controlled a fancy rudder that I made (Kitchen rudder controlled by two servos), an electric engine and read the inputs going into a LCD on a fluxgate compass. Based on what it read, it speeded up, turned right, etc.

Things must have moved on a lot since then (no more assembler language or Modula-2) but it can't be too hard to program a microcontroller (Android phone?) to know what gearing you have on the bike, what gear you are in at any time and then (based on whether it gets an "up" or "down" command and the gearing table) change up or down. A short press could mean just one change, a longer press could mean make sure you are in the biggest or smallest chainring).

To get it to fit in with the Ultegra Di2 stuff that you have found you would need to get the microcontroller to take inputs from the up/down buttons (nothing to do with Di2). That's easy. The program would read these and then close one of four momentary switches into the little "black" boxes that you discovered in the shifters (e.g. if the input is "down" and it decides just to move the rear derailleur down then it virtually closes the momentary switch to the "black" box that normally deals with "down" - if it decides it needs to change chain rings it virtually closes the "down" switch to both front and rear derailleur).

Saying it like this doesn't sound too hard. And I don't think it is. You (or me, or whoever) just need to do what you did but insert a little computer between your new momentary switches and the two "black" boxes.

The question for me then is do I want to spend a lot of money on Ultegra Di2? Not sure yet but I have just bought four buttons...

Out of interest, if you have a photo of the switches on the bullhorns, I'd love to see how you have done them.
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Re: DIY Ultegra Di2 TT [Dead Keen] [ In reply to ]
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The guys at Fair Wheel bikes have already done most of this creating a custom programmed sequential shift mtn bike using DA Di2.

One of the reasons that you can't use just one button for the front in a stock format is that you'd, as you noted, need a logic board to interpret the if/then logic on which way to shift the front depending on current position. Plus, honestly, I don't know if this would be a good idea as I know at least in my own case, I've been in the "what front ring am I in?? well I'll just try to shift to the ring I want to be in without looking to make sure that's where I am..." position and if I say I was trying to get to the big ring and was already there... well a single button push would obviously suck.
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Re: DIY Ultegra Di2 TT [Dead Keen] [ In reply to ]
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Hello,

As was mentioned earlier, sequential shifting has been developed for DA di2. Problem is the communication protocol is different than ultegra di2 so in order to work in sequential shifting for ultegra, a whole new system would have to be developed. It is a neat idea so its definitely something i would like to attempt. Theres two ways of approaching it: one is the way you suggested, the other would be to build a controller that uses canbus itself and will therefore do away with the need of the "black boxes". Right now, i am still in the process of decoding how the system is communicating. Placing a controller in line with the black boxes would be the easiest but probably the bulkiest option and keeping things internal is a priority.

Half the fun of having a di2 system is looking for ways to modify it....and i definitely like the challenge. Be sure to update with anything you develop!!

For the bullhorn shifters, I used the cateye remote buttons. They are small, flat, surface mount, tactile switches. I use vision levers and found there was plenty of room for two on each one. The good thing about those buttons is that they are surface mount...you can still run the wires internal but mounting the switches doesn't require drilling and can be placed anywhere. I will take some pictures and post them here when I get home.

Thank you for suggesting these ideas and have fun on your project!
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