As I mentioned yesterday, Sheldon Brown has passed away. Though I never met him, I always admired the wealth of information he made accessible to the universe through his website. True to cheaphack's mission, I'm going to feature two hacks from his website:
(1) Home made drop bolts. Need to put smaller wheels (such as 700C) onto a larger frame (say, one that requires 27")? It all fits alright, but suddenly your caliper brakes don't reach the rim.
Sheldon's solution was to cut two short lengths of aluminum plate stock, allowing you to drop the brake mechanism. Since you have two plates, this hack can be relatively strong.
(2) A Fixture to aid in Brazing Cantilever Bosses. Ever want to build your own frame? I've always wanted to. The tricky part about bicycle frame building is that you need to put a lot of effort into ensuring symmety in the frame. It can be difficult to keep things in position while you braze.
Cantilever bosses are one such example. These are the little cylinders that stick out of the seat stays and fork of a mountain or cyclocross frame, which allow cantilever brakes to be mounted. Like most tools, industry will sell you one for a lot of money, but Sheldon decided to build his own and save a lot of money. This design features two cool pieces. The "clamping part" on the right, and the boss holder on the left.