The audiences are as follows:
 - bike enthusiast who wants to configure a touring/commuter bike
 - someone who is looking at certain bike models and wants to survey availability of replacement parts.

My understanding of who would be interested is changing as I learn. I know that I, myself have always been interested in how bikes go together. But who else? There definitely are people who are building up bikes and researching this information. So they are probably looking at Surly.

So now I'm thinking that the audience somebody who commutes regularly and is an experienced bike owner. There are numerous YouTube videos of people talking about the stuff on their bike. Those are the type that would browse through an encyclopedia.

For example someone who commutes every day and may do weekend trips. Someone who has already had to replace numerous parts on previous bikes. The question then is:

1. Phil H
    Equipment expert. Does endless bike research, does exotic off road touring trips. Eg: Jones bikes. Mostly interested in geometry as opposed to maintenance. Very aware of all the videos. Not particularly interested in commuter and low cost bikes.

2. Dave W.
    Rides long distance to work every every day on mountain bike for exercise. Rides in all weather and says he has been forced to replace his entire drive train every season, and sometimes more than once. Used to fix everything, but nowdays bikes have gotten so complex he has a shop do it. Recently bought a second bike for a couple of hundred dollars: an old Rocky Mountain "beater" bike 7 speed. Does not have attachment.

3. Darlene
    Drives year round. Bought a steel frame Salsa and had it built up with 9 speed components, and Hollowtech crank. Replaces her drive train every year. This year's bill was $600 to replace chain rings, cassettes, bottom bracket, cables, etc. She hasn't spent a lot of time researching parts, relied on expert advice from mechanics Mighty Riders.

4. John B
    Had mountain bike stolen, bought new Norco Indie hybrid "commuter" bike for $1000. Assumes parts will be available, not likely to spend a lot of time researching.

5. Carol E
    Has several bikes, did a huge amount of bike research for latest steel frame Salsa with Roloff hub.

6. Steve
    Has done dozens of touring trips. Just bought a new bike from Specialized in the $2900 range. Interested primarily in ride quality, not maintenance. No longer commuting.

7. Denise
    Rides a lot mostly recreational. Recently got a bike with inappropriate gears, now wondering what cranks/cassettes could be used to convert it. Of course she could go to a store and might be lucky enough to find a mechanic to walk her through all the issues. But good mechanics are also pretty busy, and don't necessarily have time to walk everybody through the logic and parts availability.