Making brakes that slow down a bike is easy. But making them light, powerful, efficient, adjustable and durable takes a lot of experience and smart design. That's the stuff that Avid has made look so easy for years.
If you're fixing an older bike with V-brakes these Single Digit 7s are just what the doctor ordered. But if you want the most stopping power with amazing modulation and lever feel, you need to try the Shimano XT M785-B Disc Brakes.
It's hard to justify investing in high end linear-pull brakes from a manufacturing perspective because of the dominance of disc brakes now. That being said, Avid recognizes that there are a decade and half's-worth or more of well-loved bikes that still use this old standard and deserve a good replacement part when the time is right. The only reason I'm giving 4 instead of 5 stars is because I just love Shimano's old XT and XTR camming V-brakes that prevent the pads from diving as they wear.
When my OEM Avid Single digit brakes needed replacing, I "upgraded" to this (although with the sale lesser models weren't necessarily cheaper). The short noodle makes it much easier to release and reattach for wheel removal. The metal cable housing is slightly different (requiring me to adjust my cable housing), but now there's more clearance between the cable and the attachments for my rear rack. Also cap head screws instead of Phillips for tension adjustment are more convenient.
I have been using these brakes for years and plan on using them for Direct Pull / V-style brake needs in the future. These brakes are intelligently thought out and well designed, the tension springs run on a small roller mounted on a metal pin on the backside of the individual arms. The noodle is a nice unit which has the little wiper / boot which the cable passes through. The mounting hardware appears to be stainless as well as the cable fixing bolt I have seen no signs of corrosion. The pads which come with this set are the kind which slide into the holder and are retained via a metal clip making replacement easy, quick, and very inexpensive. The pads are also grabby and free of squeal if properly setup. If you are running a bike using rim brakes, these brakes are worth it.
Great brakes. Easy set-up. Stop great.
If you are in the market for good brakes at minimal cost, SD7's are the way to go. They deliver solid braking power and won't empty your wallet.