Rear suspension systems make a big difference on mountain bikes, but most such setups are a bit "much" for use on regular commuter bikes. The Type 57x bicycle was designed with that fact in mind, as it features low-profile frame-integrated rear shocks.
Currently in prototype form, the 57x came to our attention when it was recently featured at the MADE hand-built bicycle show in Portland, Oregon. It's built by New York state-based metal components manufacturer Fabbro Industries, which is also developing the technology for use in motorcycle frames.
On a mountain bike, rear suspension first and foremost helps the rider maintain traction and thus have better control of the bicycle. The system does so by keeping the rear tire in contact with the ground instead of bouncing up into the air every time it hits an obstacle. Of course, the setup also makes for a smoother, comfier ride.
The 57x is intended to bring those same attributes to urban commuters or light-off-road riders, who will presumably be encountering smaller obstacles and therefore not need such a big, complex and bulky-looking system.
To that end, the bike's four removable shocks are threaded right into the frame – there are two relatively stiffly tuned gas shocks in the chain stays, and two other softer-tuned coil-over hydraulic shocks in the seat stays. The former extend to absorb large-bump impact energy, while the latter compress to absorb smaller bumps.
"By allowing the wheel to move rearward (extension absorbers in the chain stays) and then forward (seat stay compression absorbers), we break the vibration damping into two components," Fabbro CEO Terence Musto explains. "The forward motion of the wheel acts as a 'unifying' force to link the motions."
Musto adds that while the current prototype bikes offer only about 75 mm of suspension travel, their rear suspension systems reduce acceleration experienced at the seat post by about 40% as compared to a traditional hardtail bike. "In a practical sense, this means that you can hit a 2" x 4" or a speed bump in the road at 20-ish mph [32 km/h], and stay on the seat without significant discomfort and without losing control of the bike," he says.
Plans call for complete Type 57x bikes to be available by late spring or early summer of next year (Northern Hemisphere), priced somewhere between US$2,000 and $2,500.
They will likely be spec'd similar to the two existing dual-sport prototypes, which weigh about 32 lb (14.5 kg) and feature an aluminum frame; a Shimano SLX or SRAM GX Eagle drivetrain; Shimano SLX or SRAM Guide T hydraulic disc brakes; a RockShox Judy Silver fork; and 27.5-inch wheels clad in Continental Trail King or Maxxis Rekon tires.
It is hoped that the technology will ultimately be licensed to larger manufacturers, who may integrate it into a wider range of bicycle types.
Source: Fabbro Industries