Author Topic: Di2 Failure mode  (Read 45530 times)

quixoticgeek

  • Mostly Harmless
Re: Di2 Failure mode
« Reply #325 on: 01 June, 2018, 05:21:59 pm »

Wasn't the Paris-Roubaix Sportive mentioned at one point - or am I thinking of somewhere else? World Championship Open Can competition? To let the worms out?

Well remembered. I'm hoping to do the Paris Roubaix Sportif next weekend. I am unlikely to be stupid enough to try it twice. Will ride it on my franken bike.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Kim

  • Timelord
    • Fediverse
Re: Di2 Failure mode
« Reply #326 on: 01 June, 2018, 05:25:07 pm »
Rumbled... And there was me keeping my endurance racing aspirations quiet, limiting it to only mentioning it in half a dozen threads. Damn... or something...

That and asking about Di2  :)

Re: Di2 Failure mode
« Reply #327 on: 01 June, 2018, 09:59:30 pm »
I am enjoying this thread immensely. Keep going  ;D

citoyen

  • Occasionally rides a bike
Re: Di2 Failure mode
« Reply #328 on: 05 June, 2018, 12:29:05 pm »
Upthread I commented that based on the known principles of servo operation, I could think of reasons why a top rider's electronic RD had enthusiastically stuffed itself into his back wheel. No-one engaged with that in the slightest, despite previous implications that they knew much better than I did how the system works.

I'm interested in this, since I did have the problem of the rear mech over-shifting into the rear wheel a while ago. It happened when I shifted into the lowest gear at the start of a climb. The mech was damaged enough that it needed replacing. Expensive.

At the time, I presumed the most likely cause was a bent mech hanger, but since the mech hanger broke when it happened, it's hard to be certain. I'm open to considering other possibilities.

I honestly couldn't say whether or not the limit screws were properly adjusted.

On the subject of unexpected failures, I had an interesting one on the Scottish ride at the weekend. I was keeping my Garmin topped up from a power bank via USB cable, but on Sunday afternoon, the cable failed (I have confirmed this diagnosis since I got home by charging it successfully with a different cable). Fortunately, I was close to the finish and there was enough juice left in the device to see me through, but if that had happened earlier in the ride, it would have been a problem - albeit very much a First World Problem in that the only down side would have been not having a record of my ride to share on Strava. I was carrying a printed routesheet as back-up for navigation purposes.

I know some will suggest this is further evidence for preferring a device like the Etrex that uses AAA batteries. And some will say it is evidence for preferring not to use unnecessary electronic gadgets at all. Both would be valid opinions but I'm happy enough with my choice to use a rechargeable device.

For what it's worth (ie not a lot), my four-year-old Di2 battery lasted the full 1,000km without needing to be topped up.
"The future's all yours, you lousy bicycles."

Re: Di2 Failure mode
« Reply #329 on: 05 June, 2018, 12:52:36 pm »
Jeez, that opens up a whole other can of worms:  Garmin reliability :hand:

Having lost a track for a 300 diy at the weekend because Garmin are pretty wank at software apparently ( As soon as someone else brings out radar support I'm buying!)  this is a pretty sore subject. They do seem to bring out updates which correct a few issues and introduce many more.

 My DI2, however,   which I've had longer than my current Garmin was faultless ;D

Re: Di2 Failure mode
« Reply #330 on: 05 June, 2018, 12:53:42 pm »
it might be that the low gear stop screws do wear on their seatings faster than normal in a Di2 system (and you would never know this was happening BTW, not until it was too late) and that the fault is difficult to detect, since the servo won't necessarily overshift when the bike is on the workstand.

  It might well be that the overshift will only occur when the shift is slightly delayed (because you are still pedalling with some pressure) or there is a fault of some kind.

In the workstand, I guess that correct low gear stop screw adjustment can only be inferred by screwing it in until the mech moves slightly, and then backing it off a touch. It might part of the learning curve (which would happen with any new system I guess) but then again it may be something that has to be checked more often than you expect if you want reliable operation.

With a cable-operated RD, in the workstand you just grab the rear mech and try and stuff it into the spokes (i.e. pushing through the adjustment to the stop screw  and through any slack in the pivots); if it touches then the stop screw needs adjusting. Not sure if there is a similarly pragmatic test that can be done with a (used) Di2 system.

cheers

citoyen

  • Occasionally rides a bike
Re: Di2 Failure mode
« Reply #331 on: 05 June, 2018, 12:54:54 pm »
Jeez, that opens up a whole other can of worms:  Garmin reliability :hand:

The Garmin itself worked perfectly for the whole 1000km. It was the charging cable that let me down. That's why I thought it was interesting enough to be worth mentioning - not a failure mode I had anticipated.
"The future's all yours, you lousy bicycles."

quixoticgeek

  • Mostly Harmless
Re: Di2 Failure mode
« Reply #332 on: 05 June, 2018, 12:58:14 pm »
.

On the subject of unexpected failures, I had an interesting one on the Scottish ride at the weekend. I was keeping my Garmin topped up from a power bank via USB cable, but on Sunday afternoon, the cable failed (I have confirmed this diagnosis since I got home by charging it successfully with a different cable). Fortunately, I was close to the finish and there was enough juice left in the device to see me through, but if that had happened earlier in the ride, it would have been a problem - albeit very much a First World Problem in that the only down side would have been not having a record of my ride to share on Strava. I was carrying a printed routesheet as back-up for navigation purposes.

I know some will suggest this is further evidence for preferring a device like the Etrex that uses AAA batteries. And some will say it is evidence for preferring not to use unnecessary electronic gadgets at all. Both would be valid opinions but I'm happy enough with my choice to use a rechargeable device.

For what it's worth (ie not a lot), my four-year-old Di2 battery lasted the full 1,000km without needing to be topped up.

The horror stories of Garmon failures were what made me get a Wahoo. I also have a backup logger in the form of my iridium device. Not as detailed a log, but a lot non the less.

Could you issue not be dealt with by a spare USB cable? I always carry three. So when I stop I can charge 3 devices at once (phone, iridium, Wahoo), so if one cable fails I can use on of the others. I also carry a pair of battery packs, as well as a usb-werk. Just in case.

Can you charge di2 while riding ?

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

citoyen

  • Occasionally rides a bike
Re: Di2 Failure mode
« Reply #333 on: 05 June, 2018, 01:03:36 pm »
it might be that the low gear stop screws do wear on their seatings faster than normal in a Di2 system (and you would never know this was happening BTW, not until it was too late) and that the fault is difficult to detect, since the servo won't necessarily overshift when the bike is on the workstand.

With the system being self-indexing, it seems extremely unlikely that the servo would overshift with the bike on the workstand, so yes, it would be almost impossible to detect a problem like that without going looking for it.

It's easy to be lulled into a false sense of security with Di2 and not appreciate that it requires routine maintenance just like any other system. Although the extent of the maintenance you can carry out on Di2 is obviously somewhat limited anyway.
"The future's all yours, you lousy bicycles."

citoyen

  • Occasionally rides a bike
Re: Di2 Failure mode
« Reply #334 on: 05 June, 2018, 01:08:38 pm »
Could you issue not be dealt with by a spare USB cable? I always carry three. So when I stop I can charge 3 devices at once (phone, iridium, Wahoo), so if one cable fails I can use on of the others. I also carry a pair of battery packs, as well as a usb-werk. Just in case.

I already find myself carrying a stupid number of cables since all my devices have different plug fittings - Lightning for iPhone, another proprietary plug for Di2, micro USB for various things, mini USB for the Garmin... so yeah, might as well carry another spare mini USB cable, another few grams won't kill me.

It does make me contemplate sacking it all off and returning to a simpler low-tech set-up.

Quote
Can you charge di2 while riding ?

I believe you can, but I have never needed to.
"The future's all yours, you lousy bicycles."

Feanor

  • It's mostly downhill from here.
Re: Di2 Failure mode
« Reply #335 on: 05 June, 2018, 01:23:21 pm »
On the subject of unexpected failures, I had an interesting one on the Scottish ride at the weekend. I was keeping my Garmin topped up from a power bank via USB cable, but on Sunday afternoon, the cable failed (I have confirmed this diagnosis since I got home by charging it successfully with a different cable). Fortunately, I was close to the finish and there was enough juice left in the device to see me through, but if that had happened earlier in the ride, it would have been a problem - albeit very much a First World Problem in that the only down side would have been not having a record of my ride to share on Strava. I was carrying a printed routesheet as back-up for navigation purposes.

I had both a spare USB cable, AND a spare Garmin, all programmed up and ready as a drop-in replacement!

Kim

  • Timelord
    • Fediverse
Re: Di2 Failure mode
« Reply #336 on: 05 June, 2018, 01:32:40 pm »
Jeez, that opens up a whole other can of worms:  Garmin reliability :hand:

The Garmin itself worked perfectly for the whole 1000km. It was the charging cable that let me down. That's why I thought it was interesting enough to be worth mentioning - not a failure mode I had anticipated.

To be fair, a USB A to micro-B cable is almost as easy to buy from a random shop as a pair of AA cells for the now legendary eTrex.  Shame that Garmin are still using mini-B connectors, isn't it?

simonp

Re: Di2 Failure mode
« Reply #337 on: 05 June, 2018, 01:36:13 pm »
I thought they were using micro now.

The garmin external battery for the edge 1030 gives claimed 40h total. It does away with the need for having a cable plugged in. You could top up the external battery in the dry at a control. Or have two.

citoyen

  • Occasionally rides a bike
Re: Di2 Failure mode
« Reply #338 on: 05 June, 2018, 01:54:03 pm »
To be fair, a USB A to micro-B cable is almost as easy to buy from a random shop as a pair of AA cells for the now legendary eTrex.  Shame that Garmin are still using mini-B connectors, isn't it?

As simonp says, they've switched to micro now. But I'm still using my Edge 510, which predates Garmin acquiring a clue. I think it's just about the only device I own that still uses mini.

I like the look of the external battery for the 1030, although it's yet another proprietary format.
"The future's all yours, you lousy bicycles."

simonp

Re: Di2 Failure mode
« Reply #339 on: 05 June, 2018, 01:59:31 pm »
I think we’re still pre-clue.

citoyen

  • Occasionally rides a bike
Re: Di2 Failure mode
« Reply #340 on: 05 June, 2018, 02:13:29 pm »
I think we’re still pre-clue.

Fair point.
"The future's all yours, you lousy bicycles."

Samuel D

Re: Di2 Failure mode
« Reply #341 on: 05 June, 2018, 02:32:25 pm »
The battery-life problem with Garmins is exacerbated by the quick decline in capacity of the cheap batteries they use. This can be ameliorated by not fully charging the battery or letting it become fully discharged on typical rides, saving that for when it’s unavoidable (long rides). On my regular short rides (others might call them training rides), I charge mine to about 70% usually and get home with more than 30%. This keeps the lithium-ion battery in its comfort zone and greatly extends its life.

Re: Di2 Failure mode
« Reply #342 on: 05 June, 2018, 11:49:21 pm »
Upthread I commented that based on the known principles of servo operation, I could think of reasons why a top rider's electronic RD had enthusiastically stuffed itself into his back wheel. No-one engaged with that in the slightest, despite previous implications that they knew much better than I did how the system works.

I'm interested in this, since I did have the problem of the rear mech over-shifting into the rear wheel a while ago. It happened when I shifted into the lowest gear at the start of a climb. The mech was damaged enough that it needed replacing. Expensive.

At the time, I presumed the most likely cause was a bent mech hanger, but since the mech hanger broke when it happened, it's hard to be certain. I'm open to considering other possibilities.

I honestly couldn't say whether or not the limit screws were properly adjusted.

On the subject of unexpected failures, I had an interesting one on the Scottish ride at the weekend. I was keeping my Garmin topped up from a power bank via USB cable, but on Sunday afternoon, the cable failed (I have confirmed this diagnosis since I got home by charging it successfully with a different cable). Fortunately, I was close to the finish and there was enough juice left in the device to see me through, but if that had happened earlier in the ride, it would have been a problem - albeit very much a First World Problem in that the only down side would have been not having a record of my ride to share on Strava. I was carrying a printed routesheet as back-up for navigation purposes.

I know some will suggest this is further evidence for preferring a device like the Etrex that uses AAA batteries. And some will say it is evidence for preferring not to use unnecessary electronic gadgets at all. Both would be valid opinions but I'm happy enough with my choice to use a rechargeable device.

For what it's worth (ie not a lot), my four-year-old Di2 battery lasted the full 1,000km without needing to be topped up.

Using one of the lesser known permutations of the Law of Murphy, it will be seen that mission critical failure can only occur when the mission is critical. (Thus testing for mission critical failure can only be done by undertaking critical missions). Devize des Shaddock: pas de solution sans problème!

Re: Di2 Failure mode
« Reply #343 on: 29 April, 2019, 10:26:24 am »
I had my first Di2 failure yesterday. The spring that holds the two halves of the crash protection mechanism together has decided to pingfuckit. Bloody mechanical parts!

Upper middle here, along with the screw it attached to:
https://www.maciag-offroad.de/shop/artikelbilder/normal/99525/shimano_schaltwerk2_1524226806.jpeg

I found a silicone ring in my tool bag that (mostly) held it together for the ride home (with full shifting). I'll probably cable tie it for now - hopefully I can get it warrantied eventually.

FifeingEejit

  • Not Small
Re: Di2 Failure mode
« Reply #344 on: 29 April, 2019, 10:42:20 am »
Is that part 5/6 on:
https://si.shimano.com/pdfs/ev/EV-RD-R8050-SS-4249.pdf
or another bit that's not replaceable individually?

The previous generation look a bit more complex in parts, but functionally look the same.
https://si.shimano.com/pdfs/ev/EV-RD-6870-3641A.pdf

Re: Di2 Failure mode
« Reply #345 on: 29 April, 2019, 10:57:32 am »
It's on the back of the main body, so you can't even see it on those exploded diagrams.

(It's an XT M8050, so even more complicated than the R8050, although the diagram for that is much the same)

I've found an appropriately sized screw in my junk box, so now just need to get hold of a correctly sized tension spring.

FifeingEejit

  • Not Small
Re: Di2 Failure mode
« Reply #346 on: 29 April, 2019, 11:35:09 am »
ah, yeah just a bit
https://si.shimano.com/pdfs/ev/EV-RD-M8050-5154B.pdf

I've just realized looking properly I asked if it was the spring that essentially does the chain tensioning... doh.

I'd have thought the crash mechanism would be a service part... but doesn't appear to be...

Re: Di2 Failure mode
« Reply #347 on: 29 April, 2019, 12:06:38 pm »
...I'd have thought the crash mechanism would be a service part... but doesn't appear to be...

it does seem like it is a bit of an oversight, that.

cheers

Re: Di2 Failure mode
« Reply #348 on: 29 April, 2019, 08:13:35 pm »
I am about to give up on Di2 and convert the bike to mechanical gears. I built this bike in 2012 and fitted it with the then state-of-the-art Ultegra 10 speed Di2. All was well for 5 years apart from the occasional accidental cable disconnect which was easily spotted and sorted. However, I have had 3 failures since then. All occurred suddenly when out on a ride and the cause was not obvious at the roadside, without access to mains power and/or the diagnostic computer.

Fault 1 was damage to the connection box near the bars when a cable was nipped by the clamp of a Garmin mount (my fault really) but it took a while to wear through to break the wire.

Fault 2 was sudden failure of the internal junction box in the down tube. I needed the LBS to diagnose that one as a visual examination of system didn’t provide any clues.

Fault 3 was sudden battery failure the day after showing steady green and only a short 15 mile ride the day before. Shifting both front and rear stopped dead after about 7 miles the following day. The described FD followed by RD failure didn’t occur. Got home, charged battery and it all works again, but for how long?
It’s a 7 year old battery so I would expect some loss of charge.

None of these issues cost much to fix but the hassle required to diagnose the causes has made me lose confidence in the system so I’m swapping to mechanical gears now.
I am often asked, what does YOAV stand for? It stands for Yoav On A Velo

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: Di2 Failure mode
« Reply #349 on: 02 May, 2019, 10:59:01 am »
I am about to give up on Di2 and convert the bike to mechanical gears. I built this bike in 2012 and fitted it with the then state-of-the-art Ultegra 10 speed Di2. All was well for 5 years apart from the occasional accidental cable disconnect which was easily spotted and sorted. However, I have had 3 failures since then. All occurred suddenly when out on a ride and the cause was not obvious at the roadside, without access to mains power and/or the diagnostic computer.

Fault 1 was damage to the connection box near the bars when a cable was nipped by the clamp of a Garmin mount (my fault really) but it took a while to wear through to break the wire.

Fault 2 was sudden failure of the internal junction box in the down tube. I needed the LBS to diagnose that one as a visual examination of system didn’t provide any clues.

Fault 3 was sudden battery failure the day after showing steady green and only a short 15 mile ride the day before. Shifting both front and rear stopped dead after about 7 miles the following day. The described FD followed by RD failure didn’t occur. Got home, charged battery and it all works again, but for how long?
It’s a 7 year old battery so I would expect some loss of charge.

None of these issues cost much to fix but the hassle required to diagnose the causes has made me lose confidence in the system so I’m swapping to mechanical gears now.

Was this the old style DI2? (external battery, non CANbus comms etc) (I think it changed around 2014 but can't find the detail at the moment - there used to be a web site about this somewhere)


ETA: For future reference by anyone, here's a useful site:
http://carltonbale.com/shimano-di2-everything-you-need-to-know/#compatibility
Regards,

Joergen