The weight is only one thing that's changed since its Kickstarter two years ago.

There is a famous (among bike nuts, anyway) quote:

All bicycles weigh fifty pounds. A thirty-pound bicycle needs a twenty-pound lock. A forty-pound bicycle needs a ten-pound lock. A fifty-pound bicycle doesn't need a lock at all.

One has to wonder how heavy a lock you need for a Hummingbird bike.Two years ago Kim covered the Kickstarter launch of this folding bicycle that she called “an eye-popping, carbon fiber model that weighs a feather-light 6.5 kilograms, or about 14 pounds (or the equivalent of four pineapples, according to their video)." It was offered then at £1,100 (USD $1,685). Commenters complained, noting that “Treehugger almost always ignores the price in favor of the "exciting innovation".

© Hummingbird

Now, two years later, it is on the market and it is beautiful. It is an exciting innovation, and it’s not just the weight that is eye popping. It now weighs a little bit more (6.9 kilos, a bit over 15 pounds) and costs a LOT more: “With prices starting at £3,495, Hummingbird has spared no expense in designing the ultimate product for the urban cyclist.” However, the pound has dropped significantly against the US dollar, so that’s only US$4,604 -- a bargain. I think I can warn you now: Don’t read the comments.

© Hummingbird

It is being manufactured by race car builder Prodrive to beautiful specifications. "The lower rolling resistance of high pressure slick tyres and the lower drag of high quality sealed bearings allow Hummingbirds to go faster with less effort. Small wheels allow for a lower moment of inertia, meaning faster acceleration and more responsive steering."

Featuring the same carbon fibre manufacturing process as Prodrive’s race cars, each frame is manufactured at the dedicated composites facility in Milton Keynes....Starting as stock prepreg carbon fibre, sheets of carbon are sliced into accurately measured strips before being perfectly aligned to make the frame. The layers are then fused together into one piece, under high pressure and heat. This highly meticulous process results in a perfectly compact, strong and beautiful frame, carefully handcrafted and finished to the highest standards.

The folding design is interesting and a little more time-consuming than my Strida, and folding up not quite as small as a Brompton. But it’s really all about the weight here; 15 pounds is next to nothing for a bike.

© Hummingbird

And in answer to the question about how heavy a lock should be, the answer is the same as the 50 pound bike. At that price and weight you don’t need a lock; instead you carry the bike everywhere with you and never let go. Or, as Hummingbird partner Robert Campbell notes, “The Hummingbird truly is a thing of beauty, meaning you will never want to take your eyes off it.” Indeed, you cannot afford to take your eyes off it.

Order yours at Hummingbird Bikes.