Avid named its HS1 rotor for a design feature crucial to its performance. The company's engineers were able to reduce heat in the braking system (HS stands for "heat shedding") by utilizing cross-drilled technology. This feature keep the temperature down on long descents, thereby improving efficiency and helping to keep crucial stopping power when you need it most.
They are light and seem to perform well but so far, I have been unable to prevent the squeaking. Organic pads have helped some but still have some squeak. Sanded them and cleaned them and they got better but still not quiet. I prefer the older G3 rotors because they were much more quiet.
These are a good upgrade from standard Avid rotors but I'm sure there are better heat shedding rotors out there, like the new ones released in Avid's 2014 lineup. I have these on my 29er trail bike and one on my dirt jumper. They work great for me in both applications and seem to fit all of my needs!
Bought these rotors for my Tektro system. These rotors have been nothing but trouble. A bit of warp on one section and screeching all the time on both wheels. After the first ride I cleaned with brake cleaner to resolve, and it only worked for the first 20 mins of the ride. I wanted to throw them out in the middle of what should have been a great ride. Give me my bog standard stock 160 rotors over this BS. Wish I didn't wait 4 months before swapping rotors otherwise I would have sent them back.
I've bent both rotors on my mountain bike in the past year, so I picked up 3 of these rotors recently. Not much to say other than they are good replacement parts, solidly built, and were installed with no problems. Comes with rotor and new mounting screws.