What can I use as replacement for old Shimano L03A brake pads?

Question

I have Trek Emonda SL5 Disk 2022 which comes with Shimano 105 groupset and Shimano RT70 centerlock 160mm brake rotors. It uses Shimano 105 R7020, 11 speed shifters.

I need to change the rear brake pads as they are worn out. The old ones are listed as Shimano L03A but I cannot find those anywhere. What brake pads can I use as replacement?

Also old brake pads have different numbers listed below the L03A model (like SSH22 for Right side rear one and SS101 for Left side rear one). Those numbers are different on front and back pads.

Do I need to consider those numbers when buying replacement brake pads or just using the same model will suffice?

Answer 1

Here is a pad compatibility chart for Shimano-branded pads. There are other companies that make compatible pads (I've used pads from both Koolstop and Swissstop). You're looking for pads that are equivalent to KO3x/KO4x/LO3x/LO4x. These pads are left/right specific, so you shouldn't put them in reversed; the L-series pads are shaped in such a way that this isn't really possible.

There are definitely pads that won't fit, so you can't buy just any pad.

You'll have a choice between metal pads (also called "sintered") or resin pads (also called "organic"). Supposedly resin pads stop a little better, metal pads wear a little longer.

Those LO3 pads have been in short supply at some points during the pandemic, but checking a few mail-order places, I am able to find exact replacements or equivalent products.