ST-5510 for double chain ring?
 

I have a Shimano 105 group and I switched from a triple to double chain ring but never switched out the left shifter. I'm trying to find an inexpensive solution and found the ST-5510 which may work with both triple and double rings? Does anyone have any experience with this. I imagine it would have to be a triple shifter that you can somehow convert to a double? Otherwise it would still have the three clicks that my current shifter has and the cause of all my issues. It requires constant adjustment and it's a lot more difficult to shift. I didn't have the money at the time for the double, $200, still is at the LBS.

I would have thought a triple shifter would work with a double crank, just some extra clicks you don't need ... but I've never tried it.

I've replaced the cable and housing and it will work for a bit and then it won't drop down without adjustment, rubs, or I have to pull the shifter with my right hand to get enough tension to get it back on the top. It's extra noticeable after a long winter and weight gain and only being able to ride in the big chain ring, in CO, with lots of hills lol.

There is no reason a triple front shifter won't shift a double crank just as well. It sounds like you have a cable tension and/or limit screw adjustment problem. If you didn't readjust the front derailleur after changing the crank, that's almost certainly your problem.

Start by disconnecting the shift cable and, shifting the derailleur by hand, setting the inner limit screw to allow a firm but not overshift into the now smaller chainring and the outer limit screw to allow a good shift to the larger chainring also by hand. When you reattach the cable, set it up so the brifter uses the outer two or three clicks to shift between the two chainrings. That will leave a redundant click into the now missing granny ring. Using it by mistake will only result in a slack cable and no harm. If you arrange the shifting to use the inner two positions, a forgetful shift into the not used "big ring" position can damage the shifter.

Thanks for the awesome instructions. It has been adjusted but I will give it a double check, after the next f'n snow here in CO.

There are no double and triple specific left shifters for the 9 speed 5500 series 105. Set it up like Hillrider suggests, you don't have to change anything