One button works only with sncycro shifting, or unless you are using 1X

I tried it and did not like it

2 button gives you control over the FD

I definitely prefer the one button.
I don't like the way they have gone that both the bar end and brake shifters are single button. I run single button on the extensions and dual on the brake shifters so that I can control the FD that way. I prefer the simplicity of single button shifters on the extensions as this is where I do the bulk of shifting, for some reason I have stuffed up gear changes with the dual button extensions!

I don't have the former but I did use the latter and I went with one button (SW-9071) on the extensions for a few of reasons:

• Ergonomics
• 1x
• FD shifts when in the red
• Asthetics

In terms of ergonomics, I really wanted something to keep my reach the same as that what I had with the SW-R671 and allow me to improve my grip. The 9160s would not have allowed that and I would have had to make changes to my extensions, possibly buying new ones. Additionally, I was shifting with my ring fingers on my old setup and it wasn't the most natural thing which also compromised the strength of my grip. What's more, it meant that my grip changed slightly when shifting. With the 9071, I can use my thumbs to shift and never have to change/release my grip by any measure. I also was able to move the shifters closer together narrowing my hands as well as getting a better more secure wrap with my pinky and ring fingers.


1x is self explanatory, the dual button became obsolete.


I couple of times–through a death grip–I did accidentally shift my front ring. Thankfully, this only happened in training and I modified the button mapping to prevent this in the future. I mapped the lower buttons to shift the rear mech and top front. Since, I could only reach the bottom buttons with my ring fingers it practically prevented me ghost shifting the front.


The 9160s don't look good to me. I'm not a fan of the plug shifters even if everyone raves about them. However, if I ever find myself at an event where overall reach becomes an issue the 9160s will be my work-around.


Photos of both setups:

---

My YouTubes

I debated long and chose the 1-button. I absolutely love them. No fidgeting for the right button. Just shifting with no thinking. I would choose them again every time.

I have 2 button, but have never had one button for comparison. I use synchro shift at the moment. Right bar end controls all shifting. I've never found it to be an issue to find the right button or anything. Left bar end controls the Garmin screens. Brake shifter just operate like they traditionally would if I want to override the FD shift or something. I just feel like 1 button limits you and the only benefit, from someone who admittedly hasn't tried it, is aesthetics.