I’ve always mounted everything on my bars but am getting a new shifter and the I spec B ones are available cheaper than bar mount. My XT brakes have M785 B stamped on them, does the B mean I spec B or just Brake?

Been through the same thing recently. I think this helped…

http://www.bikeradar.com/mtb/gear/article/shimano-i-spec-a-b-and-ii-mounts-explained-44410/

Cheers. So all cross compatible except for I spec A shifters

if its any help causes confusion, I’ve got some spec b shifters and find that the mount position puts the shifters too close to my thumbs unless I move the brake levers inboard further than I’d prefer.

Given the choice again I’d pay a premium and go for bar mount.

Just to chip in as well to clarify, iSpec B doesn’t give you a rotational degree of freedom between the shifters and brake lever.

It does give you adjustment to move the pair inboard/outboard form each other.

It’s cheaper for i-spec because there are no indicators and you can’t fit them when mounted i-spec style.

Right. SO I spec isn’t necessarily better. Not bothered about indicators but do like the shifter to be where I want it.

So my I spec shifter turned up and the positioning is perfect for me. Looks neat as well