Patents unearthed by Bikerumour hint at a new fork in development by Specialized that utilises technology from their Roubaix bikes and CG-R seatpost to provide 2-4mm of vertical suspension. It will be a disc-only fork and use a bolt-thru axle. The latest patent was filed in September 2014, but there’s no indication the fork will see the light of day for a while yet.

Specialized have designed a fork with specifically shaped lower legs with two arms and an open space, to be filled by a Zertz elastomer to control the range of movement. This design provides up to 4mm of vertical movement, which while not a huge amount, would certainly make a difference on rough roads or cobbles. In essence it’s an extension of Specialized’s Zertz vibration damping features found on the Roubaix.

It’s not a suspension fork of course, there’s no spring, though we’ve had suspension forks on road bikes in the past. RockShox trialled the Paris-Roubaix SL fork some 20 years ago, with 30mm of damped suspension travel. It went on to win three editions of Paris-Roubaix, before promptly vanishing into the history books.

Comfort enhancing features though have become a key feature on the latest generation of endurance and sportive bikes. There’s the Roubaix from Specialized of course, plus the likes of the Cannondale Synapse, Trek Domane, Bianchi Infinito and Lapierre Pulsium. Each employ different designs that are ultimately intended to provide a smoother ride, whether it’s for tackling a cobbled Classic or your local roads on a Sunday morning spin.

The patent is very detailed with regards to the specification of the lower fork legs, setting out the desirable angles.

“The fork tip includes a first arm extending at an angle of 20-100 degrees (preferably 40-85 degrees, and more preferably 66 degrees) relative to the steering axis, a second arm extending at an angle of 50-140 degrees (preferably 70-120 degrees, and more preferably 114 degrees) relative to the steering axis, and an axle support coupled between the second arm and the front wheel. In one embodiment, the first arm and second arm define a gap, and the fork tip further includes a resilient member positioned in the gap.”

The pictures show a disc brake and thru-axle. Obviously with the small range of vertical movement of the axle, a regular rim brake is out of the question, so it’ll be a disc-only fork. Specialized already offer the Roubaix and Tarmac with disc brakes so no problems there. As the disc brake caliper lower mount is attached to the axle, it’ll move in relation to the upper fork. To counteract this, Specialized have used a small linking arm that allows the caliper to move upwards and remain in the ideal position over the disc rotor at all times.

Interestingly the patent clearly shows a thru-axle (though its diameter isn’t clear, it could be 12 or 15mm) which will perhaps be a necessity to provide the required stiffness for the fork. Specialized have currently stuck with regular quick release axles on their disc-equipped road bikes, so could this be the start of the much anticipated shift to thru-axles on disc road bikes?

Source: Bikerumour.