Originally Posted by
FastJake
I agree. Maybe there is some theory to this, but I ride untrue rims on beater bikes all the time and can confirm this has no effect on wearing the braking surface (except at the points that bulge out.)
What matters is using good quality brake pads and keeping the metal shards out of them. Crap brake pads will grind down any rim. mrrabit's comment on the cheap CNC'd rims is also accurate. I've seen it happen on cheap rims.
What I find weird though is these are brake pads I took off Shimano Deore brakes and installed them on my department store bicycle. Just for the whirl of it, I bought yellow Jagwire brake pads for a future touring bike project because I wanted to minimize the amount of black on the bike. I'm just hoping Jagwire brake pads will work better than the Deore. At the same time, these Deore brake pads were on new old stock brakes that were on clearance. I mean these were M510 if I remember correctly. So they may date from 2000, 2001 or 2002 or something like that. Maybe they hardened over time.