How much weight can single-track shelving mounted on brick wall hold?
If your brick is solid and does not seem to be crumbly (like in +100 year old house) then I would always suggest and even my self use and Anchor bolt - In some countries called a robolt - These are on of the best load and pull rated bolts. And I always try to use these bolts because you can never be sure about who will put what on a shelf. Using these bolts if installed correctly(not difficult) are rock solid. 


The downside to using these bolts is that you need to drill very deep into the brick. 8-10cm for a small bolt.
The upside though is that it passed the monkey test1.




All you have to do is:


drill the correct diameter holes into to the wall as straight as possible in the correctly marked locations.
Remove the bolts mechanism, feed the threaded rod through the rail and replace the bolt mechanism on the other side of the rail.
Repeat at key location on the rail.
Place against wall and insert all bolts as evenly as possible.
They sould slide in easily but you apply more pressure to get it in there.
Tighten each bolt until you feel it getting harder turn the wrench.
You want to get it tight enough where you feel enough pressure that will make you change your standing stance. That should do it. 
By this point it should pretty rock solid!




And because this is for your home and not a building site you would finish it off with a bolt "nut" cover. This will give you some extra points with the wife for paying attention to the finer details. You can get various shapes, colours and finishes. Or just paint over them.



Using anchor bolts makes you only have to worry about the bearing load of the brackets and shelves you use. But it is obvious the shelf max load should not exceed the anchors load capacity to be safe.

I have seen shelves that collapsed because the bracket could not hold the weight but these bolts stayed put!



Disclaimer: Just a bit of humour but entirely factual.

1Monkey Test


  It is a test that is taken out on shelves , hooks or other newly
  installed equipment that will be used to hang things off. The test is
  simple. Hang on the object and wiggle like a monkey. If it does not
  rip/pull out / bend or create damage to the area around it. It is
  monkey proof and guarantees to carry ridiculous load. Tested in South Africa in camping sites near nature reserves on outside fixtures