Di2 Downshift problem

richie771

Happy New Year to all.

I have an intermittent problem in that my 10 Speed Ultegra Di2 will not always downshift.

This only occurs when I take out in the wet (Like today) - this may of course be the exact problem! I thought it was supposed to be usable waterproof.

The Front derailleur is fine both up and down. The rear derailleur is the issue. I have checked the cable is tight into the right hand shift all is fine.

Like I said the upshift into the larger rings is spot on, just down to the small end is the issue. Definitely not all the time, almost always after wet weather. To downshift I have to hold the shifter in for 3-4 seconds before it will downshift.

I have today brought the bike inside to dry out thoroughly and then will WD40 the terminals - hopefully this may solve the problem.

I brought the Bike in UK but now live in Germany (British Forces) so I can't take it back to the dealer (It's over 12 Months old anyway).

Would a Firmware update help - Anyone know how much a dealer charges to perform this function?

Electric and water - Got to love that combination lol!!!

dennisn

FWIW I don't see wet weather as the real issue here. I believe you have either a connection or adjustment problem. The reason I say this is that there are millions of cars and motorcycles out there with much more complicated wiring than your bicycle and they all work very well in the wet or the dry or the dirt and mud. Now a bad connection(i.e. not done properly by either you or the shop) may in fact cause some sort of electrical interference. There is a very small chance that this could be a "factory" problem but I'm leaning toward operator error as in improper setup / adjustment or not following the instructions during setup.

Pokerface

Is it a problem with downshifting all gears? Or just into the smallest cog?

Common problems will include:

Make sure ALL connections in the entire system are clean and tight. Might be worth pulling all the cables and re-plugging them, end to end if you can. I've had the odd cable come loose.

Make sure battery is fully charged.

Make sure the gears are properly aligned.


If all else fails, one thing I once did when I suspected a problem was to take the bike to a place that had a spare mech that I could pug into the bike - then I was able to determine I had a faulty mech (and not wiring). Now I'm fortunate enough to have several bikes all with the same components so I can swap parts in and out as needed.

richie771

It was definitely moisture. Bike is dry and now downshifts (To smallest cog) perfectly. Only seems to happen when I take the bike out in the rain. I tend to be out for 3-4 hours, so guessing it gets in somehow! Thankyou to all.