Roughly 130 years ago, New Yorker August Schrader and his able son, George, applied to the U.S. Patent and Trademark Office to protect the ownership of their new invention. It was a valve. "This ...

The AroFly, however, takes a different approach – it threads onto the rear tire's Schrader or Presta valve stem. It's also claimed to be the world's smallest power meter. SUBSCRIBE.