Various clamps (in this case the seat mounts) on the bike are custom built out of solid aluminum blocks, mostly by using a belt sander rather than “real” machine tools that take more time to set up and use. The seats are BikeE parts, but he may change them out some time later.

Chris's confession about doing “machining” on a belt sander led to a side discussion about various relatively quick and dirty methods others have used. Several others use belt sanders too, and Dave Krafft recalled that Ray Brick (an exquisite builder no one would normally ever accuse of being quick and dirty) used a chop saw for a lot of his rough work! We were warned that a piece of aluminum can get very hot while being sanded, so be careful about how you hold it, Mark uses arc weldor's gloves. And, when using cutting tools to use lubrication where possible, especially on Aluminum. Half and half water and dish soap was recommended highly as a cheap and effective coolant/lube for hole saw cuts, drilling blocks, etc.