BMWs tend to rank among the most customized vehicles on the road. But the Bavarian manufacturer doesn't just make cars with four wheels. It also makes motorcycles. And this could be the coolest one we've seen yet.

Called the Revival Birdcage, it was built not by BMW Motorrad itself, but by Revival Cycles, an independent chopper shop based in Austin, Texas. And though powered by a BMW engine, it's not one that's been put into production yet. At its heart sits a prototype for the Big Boxer – a large-displacement two-cylinder engine currently under development at BMW.

Around the prototype Big Boxer engine, Revival Cycles built a titanium frame – the first time it's ever made one – and crafted everything else specially for this project as well, including the carbon-fiber suspension components.

The Revival Birdcage draws its inspiration from the racing bikes championed by legendary record-chaser Ernst Hennes in Germany in the late 1920s and early '30s. And the finished product was revealed at the Handbuilt Motorcycle Show in Austin after six months of what was surely intensive work. "This was our first time to build a frame with titanium, that alone was already a significant challenge," said Revival boss Alan Stulberg.

"We had already dreamed about this bike for years and in December 2018 we received the engine and could finally get to work," continued Stulberg. "We wanted to focus attention on the engine and that is precisely what we achieved with this completely unique frame we designed. You can easily view the engine and the drivetrain from all angles."

This is the second such project that BMW has sanctioned. Late last yea, Custom Works Zon revealed Departed, another custom bike built around the Big Boxer engine, at the Hot Rod Custom Show in Yokohama, Japan, where it won the top Best of Show award.

"The 'Revival Birdcage' turned out great and really showcases our Big Boxer perfectly," noted BMW's Timo Resch. "We will also be showing a BMW Motorrad developed concept bike featuring this engine in the first half-year of 2019. BMW Motorrad will present a series production motorcycle with the Big Boxer for the Cruiser segment in the course of 2020."

Typically focused on sport bikes, touring bikes, and adventure bikes, BMW last made a proper cruiser in the R1200C that featured alongside the 750iL in Tomorrow Never Dies. We're looking forward to seeing what it does with the new engine.