I don't do a lot of DIY stuff. When I do, it's almost always to install a rack or fenders on a bike where they don't quite fit right.

For example, I had a Muirwoods 29er that required considerable drop on the front fender, so I did this:



On my 2013 Jake, the disc-specific rack I bought (Topeak Explorer MTX disc) didn't quite work because of the bulky frame bits near the rear eyelet didn't mesh with the bulky rack mount points.



So, I filed away part of the rack mounts away.



Keep in mind now, that both of these bikes were designed to be commuters and in theory should have worked with standard accessories right out of the box, but they didn't. Stuff like that is quite common but entirely unnecessary. Just a little more thought in the original frame design would have avoided both of these projects.

The set of accessories that commuters want is pretty small. If you want to design a great commuting bike, just plan for it to work with the common commuting accessories.