Orders of the washers on threaded-stud brake shoes So today I changed my v-brake brake shoes on my old MTB to put cartridge brake shoes.

I noticed that the order of the washers was different on both brake shoes.
On the newer one the brake arm was touching both convex washers, on the older one it was touching a concave and a convex.
Here's a picture: 
I know that you can swap the big and small concave washers to adjust the angle of the brake arm, but is there a specific order for the concave and convex washers ?

On this Park Tool page we can see multiple different washer orders.

Does it depends on the brakes? Does it permit some fine grained adjustment? Does it matter?
I think it doesn't really matter.  As long as you have the two curved surfaces of the orange/grey washer pairs together, then they function as one adjustable washer.

Here's what I did in testing - while the picture is rough and the angle is exaggerated, both ways of stacking the washers works fine.  Theres a third way where both the grey concave washers press against the arm, and a fourth where the orange washers are both on the right side (ie a mirror of the left image here)



For the sake of consistency, I'd do the same thing on both sides of the wheel, but even if they were opposite I doubt you could notice a difference.



Edit: Here's the official instructions from Kool Stop about MTB brake blocks.



So they specify the convex washers should be by the brake arm, and the concave ones should face them, which is the right-most image in the earlier pictures.

Curiously, the order of the other washers is based on their thickness and the rim/frame/fork's requirements.