R7000 105 shifter - knackered??

redvision

Haven't ridden for months due to injury but today decided to try a very light roller session and found an issue with the left shifter. When I tried to change to the big ring it didn't move the mech.

The mech moves freely by hand, and when on the big ring the shifter works fine dropping it down, just won't move it back to the big ring.

Have checked the cable (it's pretty much new as was changed just before I stopped riding) and there is no sign of fraying and the tension is fine, also checked there wasn't crap in the mech itself (which there wasn't).

Seen a few videos online which suggest this is a common issue. A few show some possible fixes but haven't found one which seems to work.
Will probably book in to my lbs but before I do anyone faced this issue and found a workable fix?

Thanks

webboo

What happens if you pull the cable by hand. As I posted this I realised this is only possible with external cables.

redvision

Internal routing, so can't try 😡

racerex

I had the same problem with an Ultegra shifter some years ago. I read somewhere that a good spray cleaning inside with WD-40 would clear it up. Worked for me, worth a try before replacing the shifter. I think road grime builds up inside and prevents the shifter from re-engaging after a downshift. I turned the bike upside-down to keep the oil and gunk from running down the bar tape.

N0bodyOfTheGoat

I had issues selecting the big ring on my 105 brs505/5800 setup earlier this year, even though the cable looked tight by the front mech.

What solved it for me was loosening the front mech clamp bolt, push and hold the top of the mech over <1cm, pull the slack cable through the clamp and then re-tighten.

All good since.

edward.s

Check your 'main lever support' (a tiny little bit of plastic that is inserted where the lever pushes the mechanism) is still present. Loosing that can cause these symptoms. even if it is still present, they can wear and need replacing. To work out if wear is the issue you can insert a thin shim on top of the pad and see if the lever operates correctly.

trevor.hall12

Same as the 8000 set up ,sounds like it's not been set up properly after the cable has been changed .
There's a specific way of tensioning the cable,
Undo the cable again and turn the tension screw out a few turns .

Pull the cable thru again so it's taught ,tighten the cable clamp screw down to hold it in place

Shift into the big ring

Drop it by half a click on the shifter (not down to the small ring ,there's a half click of adjustment )

Check how the lines on the FD are aligned

If they are off turn the cable tension screw in to make them match up

The wrong and right pic below is for when it's in the big ring

If you can turn the tension screw all the way in the cable hasn't been pulled through properly at step one

redvision

Thanks for the suggestion Trevor, have checked the set up and it's all as it should be.

Have also disconnected the mech and there is no pull on the cable when I try to shift. So now fairly certain the shifter is broken - even if there is no obvious sign (looking inside it).

Will drop it off with my lbs and post back what they find.