Di2 Ultegra problems down shifting rear derailleur
05-16-14, 01:47 PM
#1
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Di2 Ultegra problems down shifting rear derailleur
Hello,
Here is the problem:
This just started happening 2 days ago. When I tap the the shift lever to down shift on the rear derailleur it sometimes takes multiple taps for the the shift to happen.
Sometimes I have to tap to shift over 10 times for it to finally shift.
Sometimes I just tap it once and it shifts.
It seems to be random.
I have experimented with various finger press positions along the shift lever as well as different finger pressures (pressing hard seems to make no difference).
Shifting up works perfectly.
The only changes I made before this happened was replace change and put on a new set of wheels w/ new cassette. I did not wash the bike nor was it impacted/crashed.
I have been using these shift levers for about a year.
If you have any ideas I would really appreciate it.
Thank you in advance
-S
Here is the problem:
This just started happening 2 days ago. When I tap the the shift lever to down shift on the rear derailleur it sometimes takes multiple taps for the the shift to happen.
Sometimes I have to tap to shift over 10 times for it to finally shift.
Sometimes I just tap it once and it shifts.
It seems to be random.
I have experimented with various finger press positions along the shift lever as well as different finger pressures (pressing hard seems to make no difference).
Shifting up works perfectly.
The only changes I made before this happened was replace change and put on a new set of wheels w/ new cassette. I did not wash the bike nor was it impacted/crashed.
I have been using these shift levers for about a year.
If you have any ideas I would really appreciate it.
Thank you in advance
-S
05-16-14, 02:06 PM
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Sorry, this is a mechanic's forum, and you need an electrician.
However based on your description, I suspect a bad contact in the lever, possibly due to some age related corrosion. I don't know if these contact points can be exposed so you can clean them up, or whether a contact cleaner spray might help.
Hopefully, someone who's experienced similar issues might help, otherwise, visit a Di2 familiar mechanic, or email Shimano tech for guidance.
However based on your description, I suspect a bad contact in the lever, possibly due to some age related corrosion. I don't know if these contact points can be exposed so you can clean them up, or whether a contact cleaner spray might help.
Hopefully, someone who's experienced similar issues might help, otherwise, visit a Di2 familiar mechanic, or email Shimano tech for guidance.
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An ounce of diagnosis is worth a pound of cure.
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“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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05-16-14, 02:06 PM
#3
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Double check the connectors at the derailleur and shifter. And if you have access to the block in the middle, check that, too. Otherwise, find someone or some shop with the diagnostics to plug it in and see what's up.
There's a special tool for dealing with the electrical connections -- use it to make sure the plus are firmly seated into the components.
There's a special tool for dealing with the electrical connections -- use it to make sure the plus are firmly seated into the components.
05-16-14, 06:48 PM
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check the switch contacts. you need a torx t5 to remove the 2 buttons. i would try cleaning the contacts first. the diagnostic function in the e tube software is helpful too. it can narrow down the issue
05-16-14, 08:17 PM
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While I agree that the problem's description seems to be hardware and not adjustment I will take this opportunity to add that the different wheels and cassette could be slightly differently positioned WRT the old cassette. In a mechanical system this would then require a small bit limit screw adjustments and cable tension. But the statement of having to push the shift "button' many times to get a shift motion says it's likely the button or contacts. Andy.
09-25-19, 12:12 AM
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No it is the same issue as above, it only shifts down the cassette now and again, some times there no trouble at all and the while out on a ride it will stop shifting down the cassette for a bit. always shifts up the cassette no problem. I think it may be the shift button.
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