Sora front derailleur friction shifter I have Sora front derailleur (bottom-pull), and I want to use friction shifter with it. I installed Dura Ace bar end shifters (on thumb shifter mount).

No matter how I adjust the tension the shifter doesn't hold position. It always pulls to the smallest chain ring. I wonder is there anybody who come across something this.

I begin to think the combination of derailleur and shifter is not compatible.
Any thoughts will be appreciated.
You may be able to adjust the friction. Adjusting the tension in the cable probably won't help.  

This is a bit of a known issue with some combinations:


https://www.bikeforums.net/bicycle-mechanics/1069395-shimano-rd-5701-hard-shift-friction-shifters.html
http://forums.roadbikereview.com/components-wrenching/shimano-friction-shifter-adjustment-183941.html


Unfortunately you're unlikely to be able to find a weaker return spring to fit.