I recently upgraded the brakes on my Civia from Avid BB5 Road discs to Avid BB7 Road discs. I’ve had good luck with BB5′s in the past and they were performing well on this bike, but when an opportunity arose to sell my existing brakes, I went ahead and made the switch.
The differences between these two brakes are subtle. The main difference is that the BB5 has a pad adjustment knob only on the inboard pad, whereas the BB7 has adjustment knobs on both pads. The ability to adjust both pads makes the BB7 slightly easier to set-up and keep adjusted properly.
The BB7 also has larger brake pads which provide slightly more braking power and what feels to me like slightly better modulation. They should be less likely to overheat in touring conditions, though that’s a moot point for commuting. Probably the biggest advantage of the larger pads is that, due to their larger surface area, they don’t need to be replaced as often as the smaller pads in the BB5.
One disadvantage of the BB7 is that is doesn’t have a barrel adjuster on the brake. It’s a bit perplexing that the BB5 is supplied with a barrel adjuster, but the more expensive BB7 only has a stationary stop. Avid does supply an inline barrel adjuster with the brake that can be inserted into the housing up near the handlebar, but an adjuster on the brake would make more sense, at least on the road version of the brake.
The BB7 comes supplied with metallic brake pads designed for use with their rotors. My bike is outfitted with Shimano rotors which are not recommended for use with metallic pads. I could have swapped the stock rotors for the Avid rotors that came with the brakes, but it would have required an adaptor for the Center Lock disc mount on the Alfine hub, so I opted to stay with the Shimanos. Because of this, I also ordered a set of Avid Organic brake pads for the BB7 calipers. It’s my understanding that the organic pads are a little grabbier than the metallic pads, though they feel great to me. They also wear a little faster than the metallic pads, though that’s not a serious concern for commuting.
There are a few other subtle differences between these brakes, none of which have much of an effect on performance.
Overall, this was not a bad upgrade. If I was building a new bike from scratch, I’d certainly spend the extra for the BB7′s over the BB5′s, but if I didn’t have an opportunity to sell my existing brakes, I can’t say the subtle advantages would be worth the full price of a new brake set.