Meet Bubbles, one of the latest builds from Rob English of English Cycles.
English is an award-winning custom bike builder. When a customer requested a super-light and low-maintenance road bike with an Alfine 11 internally geared hub instead of a derailleur, English devised some ingenious weight-saving features–including a chainstay socket (pictured below) to minimize weight and tension the belt. Bubbles weighs in at a thrifty 16.7 pounds.
Read more about the bike and see some more pictures on the English Cycles blog.