Someone reported that an Alfine dynohub w/ BB7 mechanical disc rotor and caliper weighs a little under 2kg. Maybe the integrated drum/dynamo in the Sturmey saves weight by, for example, allowing a stiffer hub shell to perform double duty or something, but given their appearances double duty seems unlikely:


Obviously the only way to settle this for the brake hubs w/o dynamos is to actually compare the weights, but considering the facts above I think it most likely that the drum brake hub is lighter than a comparable disc brake+hub. Especially if one opts to use a lighter fork with the drum brake.

Yeah, but stopping power is only half the problem; The other half is reliability and robustness. My biggest fear is discovering my brakes were tampered with or in need of adjustment as I try to stop myself from careening in front of a mac truck. For me it's way more important that I stop reasonably fast every time than that I stop instantly 99% of the time and not at all the other 1% of the time. Besides, I'm a bit skeptical of those who criticize the stopping power of drum brakes because there seems to be a bit of confusion/misinformation about how to properly adjust them with many folks "in-the-know" claiming they are just as good as V-brakes in the dry.


In any case I've decided to go with the drum brake for the following reasons:
1. I have the spokes already cut to length.
2. I'm a light rider and disc forks are almost certainly overbuilt for me. With a drum brake I can pick a fork appropriate to my weight.
3. I'll be running 23c tires and, let's face it, all the stopping power in the world isn't going to overcome insufficient tire traction.
4. The drum setup is probably lighter and cheaper.
5. The drum brake is lower maintenance and safer against booby traps/vandalism.