Given that their design incorporates hinges and locking mechanisms, folding bikes aren't necessarily synonymous with light weight. Allen Sports' new Ultra X, however, tips the scales at just 18.75 lb (8.5 kg). The carbon fiber commuter may just be the world's lightest folding bike ... or at least, the lightest one that looks relatively normal.

Along with its frame, the Ultra X also sports a carbon fiber fork, seat post, handlebar, stem, rims, crankset and saddle(!). It also features 20 x 1-1/8-inch tires, and an SRAM X9 20-speed drivetrain (with a Shimano front derailleur).

It can reportedly be folded down and locked together within seven seconds, and then wheeled around like a shipping dolly on its now-side-by-side wheels.

All that carbon fiber will cost ya, though. If you want an Ultra X of your own, be prepared to shell out US$4,999.

The next-lightest "conventional" folding bike we could find is a titanium Brompton, although claimed weights for it are more around 20 lb (9 kg). The A-Bike, on the other hand, reportedly weighs just 12 lb (5.4 kg), although it has tiny scooter-like wheels and an aesthetic that not everyone may appreciate.

Source: Allen Sports

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