Hey guys, i got around to upgrading my brake pads a couple of month ago. The original ones were stock and i switched them over to Kool Stop Dual Compound Mountain Pads. The rims are Velocity dyad. It makes the most horrible noise whenever i brake. Visual inspection reveals the actual rubber compound is building up on the rim walls. The walls are not machined and i expected them to be pretty much down to metal by now.
Any information before i proceed and probably do something stupid??

Blue skies,
kelvin

Put some toeing, see the middle of the page : https://parktool.com/repair/readhowto.asp?id=21

Try the shimano brake pads. Work well in the wet as well as dry conditions.

Get machined wall rims.

When I switched to Koolstop salmon pads, I had to remove a buildup left by the Shimano's I removed. A green Scotchbrite pad and some elbow grease did the trick. For toe in, I fold a business card in half and put it under the first 1/3 of the pad (leading edge, where the rim first contacts the pad), squeeze gently, and snug up the pad mounting bolt. (I start with the bolt slightly loose). Done one side at a time, this has worked for me, and no squeeling pads.

Thank you gentlemen. I will try your suggestions.