I wrote about this some time ago — that Shimano's BR-7800 has different arm lightening cutouts on the front and rear
(see here)

Today I had a chance to "wash" a brake,
so I was able to get some clearer photos.
By "wash," I don't mean clean it with water —
it's shop slang we use here that refers to a certain small modification.
Some of our customers come in saying "wash my brake" and bring theirs in.
I do it from time to time,
but you can't "wash" a BR-9000 series brake.


Before the "wash," I actually gave it a real cleaning.
Since this is a part that normally doesn't get washed, might as well.

↑Front C-arm rear side

↑Rear C-arm rear side
(see here)

Today I had a chance to "wash" a brake,
so I was able to get some clearer photos.
By "wash," I don't mean clean it with water —
it's shop slang we use here that refers to a certain small modification.
Some of our customers come in saying "wash my brake" and bring theirs in.
I do it from time to time,
but you can't "wash" a BR-9000 series brake.


Before the "wash," I actually gave it a real cleaning.
Since this is a part that normally doesn't get washed, might as well.

↑Front C-arm rear side

↑Rear C-arm rear side