R8050 Di2 Front Mech not shifting under load

thehighroad

Hi all,

Ultegra di2 front mech shifts great in the stand but when out on the road and any sort of resistance is going through the pedals it will not shift in to the small cog. Will shift up just fine.

Really frustrating when out and the gradient changes. Height, alignment and limit all seem ok and as I said changes fine in the stand.

Any ideas as to what may be causing this?

Cheers 🙂

StillGoing

If it's working ok on the stand, it should be working fine out on the road. Is there any noise from the derailleur attempting to shift? Are you sure that you've connected the tubes fully in the shifter as the downward pressure of your weight through the hands whilst on the hoods, may be enough to unseat the connection. Presumably you are pressing the correct button.

thehighroad

Thanks for the reply. Yes you can hear it trying to shift, it makes the usual electronic noise, almost as if it has shifted but then decides against it. Definitely pressing the right button

As you say if it works in the stand it should work out on the road, it will shift on the road but only if there is next to no power going through the pedals in which case you don't need to shift down.

StillGoing

I would start by checking the indexing again.