Much as it pains me to admit that I sometimes read velonews ... and it pains me even more to admit that sometimes I read Zinn's articles ... But I did find this post most interesting:
Lennard,
After using it a year, I have nothing but praise for the Shimano Di2 system. This past weekend, however, I was in southern Indiana for a team training camp, and had a problem. We had some pretty serious rainstorms one day, and there were many deep water crossings we had to cross, as some of the roads were flooded. The water was about axle deep (and dang cold too!). The bike worked flawlessly.
The next day’s ride started off well, but after 20-30 miles the rear derailleur acted up. When I pressed the “Y” button (to grab a smaller tooth in the back), it actually shifted to a larger tooth. After pressing the button a few more times it would sometimes go one way and other times the opposite direction, and other times unresponsive. The “X” button was unresponsive at times too, but then all of a sudden it would work for a few shifts. I never noticed the “X” button shifting the derailleur both ways … just the “Y” button.
This whole time, the front derailleur worked perfectly. The battery was freshly charged. Anyways, after returning home to Wisconsin, and driving through high 80 degree temps with lots of wind, things must have dried out or something. When I got home, I put my bike in the stand, and it shifts perfectly again. Needless to say, I’m a little nervous about getting caught out in the rain now. Unfortunately, I don’t have the diagnostic tool Shimano makes for testing. I know the shop I bought the bike from doesn’t either. I’m guessing the tool wouldn’t find anything anyways, unless it acts up again.
Would you or someone at Shimano have an idea of what’s going on?
— Steve
Answer from the guru of electronic shifting, Shimano’s Wayne Stetina:
There is definitely water in Steve’s system somehow. I had identical symptoms recently on a bike with a minor cut in the rear harness to the rear derailleur – minor visible damage. But it was only a problem in heavy rain, including delayed shifts, then occasionally multiple shifts.
It’s also possible the plug into the rear derailleur somehow leaked. For that, use air to dry it out completely, then use some electrical conducting lubricant and re-plug it in securely.
If you can’t find visible cable damage, the first thing to check if it ever malfunctions again is whether pushing the X and Y levers both indicate battery charge. If yes, and the front derailleur works normally, everything in front of rear derailleur cable (and rear derailleur) is good. Then try to unplug the rear derailleur, dry out any water (Kleenex or air?) then re-plug it in securely and see if it works again.
If you go to a shop with a Di2 system checker, you need to spray from the front derailleur back to the rear derailleur with a high-pressure garden hose until it malfunctions to diagnose that way.
— Wayne
So can someone remind me again - how is this system an improvement on cable operated shifting?
Lennard,
After using it a year, I have nothing but praise for the Shimano Di2 system. This past weekend, however, I was in southern Indiana for a team training camp, and had a problem. We had some pretty serious rainstorms one day, and there were many deep water crossings we had to cross, as some of the roads were flooded. The water was about axle deep (and dang cold too!). The bike worked flawlessly.
The next day’s ride started off well, but after 20-30 miles the rear derailleur acted up. When I pressed the “Y” button (to grab a smaller tooth in the back), it actually shifted to a larger tooth. After pressing the button a few more times it would sometimes go one way and other times the opposite direction, and other times unresponsive. The “X” button was unresponsive at times too, but then all of a sudden it would work for a few shifts. I never noticed the “X” button shifting the derailleur both ways … just the “Y” button.
This whole time, the front derailleur worked perfectly. The battery was freshly charged. Anyways, after returning home to Wisconsin, and driving through high 80 degree temps with lots of wind, things must have dried out or something. When I got home, I put my bike in the stand, and it shifts perfectly again. Needless to say, I’m a little nervous about getting caught out in the rain now. Unfortunately, I don’t have the diagnostic tool Shimano makes for testing. I know the shop I bought the bike from doesn’t either. I’m guessing the tool wouldn’t find anything anyways, unless it acts up again.
Would you or someone at Shimano have an idea of what’s going on?
— Steve
Answer from the guru of electronic shifting, Shimano’s Wayne Stetina:
There is definitely water in Steve’s system somehow. I had identical symptoms recently on a bike with a minor cut in the rear harness to the rear derailleur – minor visible damage. But it was only a problem in heavy rain, including delayed shifts, then occasionally multiple shifts.
It’s also possible the plug into the rear derailleur somehow leaked. For that, use air to dry it out completely, then use some electrical conducting lubricant and re-plug it in securely.
If you can’t find visible cable damage, the first thing to check if it ever malfunctions again is whether pushing the X and Y levers both indicate battery charge. If yes, and the front derailleur works normally, everything in front of rear derailleur cable (and rear derailleur) is good. Then try to unplug the rear derailleur, dry out any water (Kleenex or air?) then re-plug it in securely and see if it works again.
If you go to a shop with a Di2 system checker, you need to spray from the front derailleur back to the rear derailleur with a high-pressure garden hose until it malfunctions to diagnose that way.
— Wayne
So can someone remind me again - how is this system an improvement on cable operated shifting?
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