Hand numbness is a very common complaint among cyclists, and one of its major causes is road vibrations being carried up into the handlebars. Over the years, various companies have attempted to address the problem via suspension handlebar stems that incorporate coil springs, air-sprung shocks, or elastomers – and they’ve all looked a little "unusual." The ShockStop is the latest take on an elastomer-based suspension stem, but it looks completely normal.
The device has a forged 6061-T6 aluminum alloy body, inside of which is a pivot point (incorporating sealed cartridge bearings) and two interchangeable elastomer inserts – each stem comes with several sets of the inserts, in varying levels of stiffness.
When the front wheel hits a bump in the road, the stem absorbs much of the energy by pivoting 1 to 2 cm (0.4 to 0.8 inches). Its compliance is determined by the stiffness of the inserts, as selected by the user based on personal preference and riding conditions. That said, it’s intended mainly for road riding.
It’s also important to note that the ShockStop does not allow the bar to flex laterally (relative to the stem), so it shouldn’t affect steering.
Should you be interested, the device is currently the subject of a Kickstarter campaign. It’s available in a variety of lengths and angles, and should fit most road, hybrid, and commuter bikes. You can get one for a pledge of US$89, assuming it reaches production. Potential backers might also want to check out the Bam City handlebar, in which the bar itself flexes to absorb vibrations.
Redshift Sports, which is the company behind the ShockStop, previously had success crowdfunding its Switch Aero System, which allows a road bike to be used as a triathlon bike.
Source: Kickstarter
So the patent would have expired in 2014 in not earlier, which may explain the appearance of multiple offerings. Thudbuster patent also expired in 2015.