What frustrates /n/ most about bikes, bike parts, bike accessories, or anything mechanical that could be fixed or needs a solution?

I'll start: the state of tubes is unacceptable. It's unreasonable that we can't make a tube that doesn't pop over the smallest things, leak too much you can't ride on it in a day, and cost less than $10.

Note: this is not a thread about types of cyclists or bikes you hate, or about hating bikes in general.