While we know them more for their Double Barrel shocks these days, Cane Creek has likely been making headsets since before you could ride a bike without training wheels. That was also around the same time that people were considering steering dampers for their mountain bike (remember Hopey? They're still at it, by the way), but steering dampers may be coming back around, albeit aimed at the e-bike and commuter market. The Viscoset is far too interesting to not show you guys, however, and I also wouldn't be surprised to see it show up on the odd downhill bike.
First, let's answer the why. Cane Creek had an e-bike manufacturer come to them with an issue: some of their bikes were steering very, very poorly, to the point where speed wobble was becoming an issue. The cause of the trouble? E-bikes, and especially commuter-style e-bikes, often have their heavy battery located towards the rear of the bike which, along with the rider's position, puts a massive weight imbalance towards the rear axle. Further compounding matters is how many city-styled e-bikes have only a long down tube connecting the front of the bike to the back, which isn't exactly the most torsionally rigid design.
• Steering damper headset
• Stacked, alternating keyed clutch plates
• Damping grease between clutch plates
• Upper headset cup only
• Press-in headset cup only
• Weight: TBA
• MSRP: TBA
The result of the relatively flexible frame and odd weight imbalance can sometimes be a speed wobble, which is a scary thing to someone who's only using their bike to get to work or pick up groceries. So Cane Creek needed to come up with a headset that did the job of a steering damper but still looked like a headset, and that would be both dead simple and reliable. Enter the Viscoset, a headset that's also a steering damper.
Alternating keyed clutch plates with special damping grease between them provides steering resistance.
The Viscoset still needs to do the job of a headset, so you'll still find a standard looking headset cup but also one that's a few millimeters taller than normal. This is because there's a sealed bearing in the cup as per usual, but above it is stacked a number of thin clutch plates. Half of these plates are keyed to lock into the cup to keep them from rotating, while the other half are keyed into the compression ring so as to turn only with the steerer tube.
The clutch plates are also stacked up alternately; the headset cup is obviously stationary in the frame because it's pressed into place, and the compression ring clamps down onto the steerer tube when you preload your headset.
You can see the keyed clutch plates and how half of them lock into the compression ring.
Cane Creek then fills the gaps in between the clutch plates with a very special damping grease that provides resistance but in a smooth way. You know the 'oh shit' handles in your car and how if you let them go they'll fold back up slowly? Or how the dials on a decent stereo turn smoothly but they're not loose? That's damping grease at work, and with the alternating plates stacked up next to each other with this damping grease in between them, the Viscoset provides a similar feel to an 'oh shit' handle or stereo dial - it turns smoothly, but there's certainly some resistance there.
The amount of damping can be changed by using different viscosity grease, or even by fitting slightly different clutch plate layups, but the Viscoset isn't like a speed-sensitive fluid-style steering damper like you'd find on some motorbikes, so there's more resistance and it's applied in both directions. The design does provide a relatively low stack height considering what it does, but it's still a few millimeters taller than a normal headset, and it will obviously only work on bikes that take press-in headset cups.