2.3mm thick TRP 6-bolt rotors in 203mm.

Merlin only have them in 203mm, but they’re also only £8.99 each.

https://www.merlincycles.com/trp-r1-6-bolt-rotor-282001.html

I bought some of these the other day to replace some worn out (1.1mm – eeeek!) Shimanos.
I’m pretty sure there was a similar psa for these a couple of weeks ago, but they were 180mm only back then. Didn’t bother with it because I needed 3 203mm to go with it (2 bikes with worn out rotors) How I wish I’d bought one! Now hoping the 180s will be back in stock soon.

Surely these are .5mm too thick for Shimano?

Some go for a thicker rotor to try and influence lever feel.

APF

Some go for a thicker rotor for resistance training.

Surely these are .5mm too thick for Shimano?

Some go for a thicker rotor to try and influence lever feel.

Unless the system really can’t accommodate the pad thickness and rotor it’s just adjusting the position of the pistons, it won’t affect feel in terms of freeplay and reach.