Shimano Di* do and do not.

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Mr Haematocrit

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It appears that as electronic shifting becomes more affordable and more widely available many members of this forum are now getting bikes fitted with this.
I have been thinking about creating a thread for a while documenting difference between Ultegra Di2 and Dura-Ace, Tips and Tricks, Common Faults and Troubleshooting the system, how to do custom battery installations, custom shifting buttons, and other things which may interest such as mtb di2, bent di2.

I am a massive fan of Di2 and very enthusiastic about it, I do not however claim to have extensive knowledge of the system, what I know at thus point has been learn't by trial and error and research.

Note : from this point forward Ultegra specific information will be refereed to as Ui2 and Dura-Ace as Di2
 
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Mr Haematocrit

Mr Haematocrit

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Differences between Di2 and Ui2 :

One of the questions I get asked most often is if Di2 is vastly better than Ui2 and my opinion relating to this. Having used both systems extensively over time my thoughts are placed below. This information is my opinion and nothing else. It is not a conclusion based on scientific research but my own experiences and beliefs.

Weight :
Ui2 is heavier - forget the quoted weights as component weight does fluctuate slightly but generally Ui2 weighs around 200 grams more than Di2
Size :
Ui2 components are generally larger where servo's are mounted, this is due to using slightly larger and less expensive servos than found in Di2 derailleurs
Brake Levers :
Ui2 brake levers are alloy instead of carbon
Control Box :
The Control box on Ui2 has a nicer finish than Di2 and is slimmer
Loom :
The loom on Ui2 is slimmer and the cable ties clip on and off compared to Di2
Compatibility :
Di2 uses a five pin connector that has specific mounting points within the loom, Ui2 uses two core wiring based on CANbus which is a technology that allows networked devices using multiple controllers to communicate with each other.
Durability :
Ui2 is waterproof when its connected, Di2 requires heat shrink and is less resistant to the challenges of weather.

Ui2 vs Di2 - Living with them
Ui2 front shifting quality as long as it features a Ulegra or DuraAce crankset is identical to that offered by Di2 anyone who trys to tell you otherwise is attempting to justify the more expensive Di2 they have on their bike. The only thing which Di2 has to offer with regards to front shifting is a drop in weight and it is quieter due to using better servo's
Ui2 rear shifting does however lose out a little to Di2 not only is it a little more noisy but dropping down a gear feels less refined and slick, When shifting under load it feels a little clunky compared to Di2. Under regular shifting the experience is pretty much the same.
(I have seen some budget Ui2 bikes which do not have a Shimano cassette this can increase that clunky sensation)

What Do I run and Why?
I like running Di2 and the reason for this is that it has a slightly more polished look about the components. It is also easier to modify than Ui2 due to the Ui2's CANbus system which makes things a little more challenging (but not impossible, more on this later)
If you require electronic shifting and do not wish to modify the system then imho Ui2 is a better system and more resilient to the weather, but this is at the expense of flexibility.

more coming soon :biggrin:
 
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Mr Haematocrit

Mr Haematocrit

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Tips, Tricks and Trouble Shooting.
  • Only use 27 tooth cogs.
    The ten speed Di2 should only be used with a 27 tooth cassette, many people try the Dura-Ace 7900 11-28 cassette, simply don't do this as it results in frequent chain hangs and drops. (update : Ten speed Ui2 is apparently not subject to this issue as stated in this thread)
  • Don't pull the connections
    There is a removal tool for taking the connections out, use it otherwise you may have to buy new loom sections. (Di2 tool = TL-EW01 , Ui2 Tool = TL-EW02)
  • Continue being able to count to ten
    When you first connect the battery to the system it powers the motors on the derailleurs enough to pinch your fingers. When this is under power by the battery is is very very difficult to move the derailleur enough to release your fingers (apparently, so I have heard from somewhere :whistle: )
  • Do not Jetwash
    I have seen a number of systems with issues after bikes being jet washed, no science, no supporting evidence other than experience. Ui2 and Di2 do not like being jet washed imho.. Do so at your own risk.
  • Battery Flat on a Ride
    You deserve to push your bike home for being so stupid, although the system actually goes into limp home mode. First the front shifting will stop to save energy, the the rear. You should however never be in this position as there is a battery check which should be carried out after every ride. To check the battery's charge simply hold down a shift button and look at the control box LED, solid green is 100%, blinking green is 50%, solid red is 25% and blinking red means your gear selection is about to be limited shortly.
    If you do drain the standard battery you will have about 180 shifts on the rear after the front shifts stop working.
    Charging time for the standard battery is approximately 90 minutes so you can get a good charge in while you get dressed for your ride. You have no excuses.
  • Dropped your bike and it no longer shifts?
    These systems have a protection circuit built into them so that when the derailleur gets forced in a fall no damage is done to the system. To reset the system hold the button down on the LED control box for five seconds until the red light flashes.
  • Bottom Bracket Badness
    When servicing or working on your bottom bracket take exceptional care to ensure that you do not catch or damage the internally routed wires.
  • Intermittent Shifting
    This is usually a symptom of the standard battery being mounted externally on the frame set, in an area which is exposed such as the downtube or around the chain stays when your bike gets wet you can get moisture on the battery terminals, clean the the battery terminals and protect the battery contacts from further moisture. Shimano sell a special grease for this purpose (I use petroleum jelly but this is not a recommendation) I have equally seen standard battery setups wrapped in cling film which I would not advise as although this keeps water out, It can also help keep it in. Im not a fan of WD40 or similar as it places a glaze on the battery and makes it look terrible.
  • Minor Shift Adjustment
    To do minor adjustments which is also referred to as trim mode hold the button down on the LED control until the red light stays on. Tap the forward shift paddle for small advances of shift (when downshifting to bigger cogs), rearward shift paddle when retarding shift (when up shifting to smaller cogs) high and low grub screws provide traditional hard stop settings.
More coming soon ^_^
 
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Mr Haematocrit

Mr Haematocrit

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Battery Modifications :
  • Background
    When Di2 was first seen in the pro ranks it was pretty much used as Shimano intended, over time battery placement seemed to be a challenge with it regularly moving over various teams bike apparently seeking optimal placement. When specialized released the Venge areo bike battery placement seemed to become even more important as it impacted the aerodynamics of the bike. Team Highroad took the steps of placing the battery inside the seat post of the bike of Mark Cavendish, which is why the seat post battery conversion is commonly known as the Cav Conversion.
    http://www.bikeradar.com/gear/article/pro-bike-mark-cavendishs-htc-specialized-mclaren-venge-30158/
  • Pro's
    With a seat post battery you get to hide that fugly standard battery, you also end up with a lighter system as the seat post battery does not have a heavy mounting system and the battery is not wrapped in plastic, you can also increase the battery capacity if you wish at this time and put in place in bike charging. Once you have done this mod you have a standard fugly shimano battery which you can sell along with the charger and mounting system.
  • Con's
    If you run Di2, none do it now !!!! -- If you run Ui2 the CANbus interface which as previously stated allows networked devices to recognize one another makes this a little more challenging but not impossible. You require components to get the system to recognize the new battery as part of the system, Shimano do not sell these so you have to break apart working components to claim them as such if you are taking the DIY option you have nothing to sell to get some money back :sad:
    This is the same issue with custom shifters for Ui2 as such if your going to hack the system Di2 is a better starting point.
  • What are my other options.
    DIY basically is your last option, there are many options available from converting the original battery to an internal version, to using the battery cells from RC cars, to building your own battery packs... If you want more information relating to DIY and pointing in the right direction please feel free to message me. the options are to extensive to discuss in a general information thread like this
 
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Mr Haematocrit

Mr Haematocrit

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Custom Shifting Modifications
  • Shimano SW-7972 Sprint Buttons
    The shimano sprint buttons are an official additional shifter for the electronic group sets, its usage is like a hair trigger, a twitch of the thumb and it changes gear. This shifter can be positioned anywhere on the drops and is popular with sprinters such as Mark Cavendish in the pro ranks
    A great review of the sprint shifters can be located at Bike Radar.
    http://www.bikeradar.com/news/article/shimano-dura-ace-di2-sprint-shifter-first-ride-review-29302/
  • The SW-7972 Buttons
    This image shows the full buttons, the bar clips along with the loom plug.
    SW-7972.jpg
  • The SW-7972 Buttons
    The image below shows a close up of the sprint buttons
    botton.jpg
  • The SW-7972 Buttons
    The image below shows the sprint buttons fitted to bars and ready for use, note that you have to cut the bar tape to expose the buttons, you can see the positioning of the hand ready to flick the button with the thumb for lightening shifts
    2SW7972-WHAND_2760965.jpg
  • Living with sprint buttons.
    I have tried a number of different shift button combinations on my bikes and although many work well, they can have a certain novelty value and after a while you do not use them as often as you think. Sprint buttons however do not fall into this category and remain on my bike, you can view my album to see them on my Venge. They remain non invasive, easy to fit and work every bit as well as they suggest. You can not begin to explain just how slick they are, hair trigger does not describe the action subtlety enough, its more a trip wire sensation. Soon as you put any pressure however slight on the button... Boom you have changed gear, Awesome !! - If you spend a lot of time in the drops, then these are made for you.
  • Shimano SW-7970 Satellite Shifter
    The shimano satellite shifter is an official additional shifter for the electronic group sets, its meant for people who spend a lot of time on the top of the bars. This shifter can be positioned anywhere on the bar tops and is popular with riders such as Frank Schleck in the pro ranks
    A great review of the satellite shifters can be located at Bike Radar.
    http://www.bikeradar.com/news/article/new-satellite-shifter-for-shimano-dura-ace-di2-24933/
  • SW-7970 Satellite ShifterThe image below shows the satellite shifter with loom plug
    shimano-di2-SW-7970-R-2011-gear11-japan.jpg
  • SW-7970 Satellite ShifterThe image below shows the satellite shifter fitted to the bars.
    DSC01485-600x399.jpg
  • Living with satellite shifters.
    The satellite shifters are great if you live on the bar tops and the sifting is great, but they simply lack the added performance offered by the sprint shifters imho. The mounting is unattractive so I generally mount them with adhesive pads. These shifters are used extensively in MTB Di2 conversions. I find it difficult to be over enthusiastic about these shifters as they most certain work well, however they offer nothing more, no additional feature set.. They offer convenience, how much is this worth to you.
More shifting coming soon
 
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Mr Haematocrit

Mr Haematocrit

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i have thrown the place markers in, as I have quite a bit of info to provide and this will take me a little time :sad:

I will also attempt to assist with any questions people have along the way, if anyone else wants to chime in with the answers please do​
 

StuAff

Silencing his legs regularly
Location
Portsmouth
Dead right on the battery life thing. One of the most frequently asked 'issues' with electronic shifting that some see with it. Cycling Active had a feature a few months back, readers testing Ui2 bikes, and three out of four mentioned it. I've heard it mentioned on FNRttCs....and it just isn't an issue, unless you're a complete numpty. Test after test of all the electronic groups, and plenty of blogs from people who've been running it for some time, tells people the batteries last for ages, and that you get plenty of warning when the thing needs a charge. Still some don't listen.
 
Tips, Tricks and Trouble Shooting.
  • Only use 27 tooth cogs.
    The ten speed Ui2 and Di2 should only be used with a 27 tooth cassette, many people try the Dura-Ace 7900 11-28 cassette, simply don't do this as it results in frequent chain hangs and drops.


  • Thank you very, very much! This was due to be my next cassette, you've saved me some cash!
 

Sittingduck

Legendary Member
Location
Somewhere flat
  • Only use 27 tooth cogs.
    The ten speed Ui2 and Di2 should only be used with a 27 tooth cassette, many people try the Dura-Ace 7900 11-28 cassette, simply don't do this as it results in frequent chain hangs and drops.

Just to confirm, that it runs ok with 11-25 etc, right? Or does it literally have problems with anything but a x-27?
 
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Mr Haematocrit

Mr Haematocrit

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Just to confirm, that it runs ok with 11-25 etc, right? Or does it literally have problems with anything but a x-27?

To be quite honest, I have not run or helped troubleshoot it with an 11-25 so can not accurately comment. I do not believe there would be a physical issue with an 11-25 but that nothing more than my gut feeling based on experiences with the system on mtb bikes as well, hopefully you would be able to clarify if there are any issues and save me from having to learn by mistake at some point. :hello:
Unfortunately I have no specific experience with 11-25 on the system at this time, sorry.
 
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