Rimpact has released a tuned mass damper (TMD) for your gravel bike to reduce fatigue and improve the bike's handling.
TMDs are already uses in F1 cars and skyscrapers, and World Cup downhill mountain bikers have used them for a couple of seasons now, with a number of companies now offering production off-the-shelf products for racers. TMDs contain a weight which is suspended between two springs, which absorb bumps by delaying the transmission of kinetic energy.
Rimpact already makes a TMD which can be fitted inside most aluminium steerer suspension forks, but the Gravel Tuned Mass Damper is the first we've seen specifically for gravel bikes. It can be run even when there isn't enough space within the steerer tube, which can be the case with carbon gravel forks.
“It doesn’t interfere with any of the fork mounts” explains Dan Hicks, the engineer behind the device. “So if you’re running bags on the forks, it won’t be in the way.”
Rimpact's Gravel Tuned Mass Damper
Rimpact says its Gravel Tuned Mass Damper leads to a 3% reduction in the impacts transmitted to the rider. This could have both handling and comfort improvements.
“A weight between two springs offers a pretty significant benefit,” says Hicks.
The device weighs a claimed 400g, which is not inconsiderable, but Rimpact believes that the handling benefits are worthwhile.
Rimpact says that setting the Gravel TMD up is easy and that it's a one-size-fits-all solution. The Gravel TMD bolts onto the outside of the fork on the flat-mount brake caliper mount. This means that riders using a rigid fork with a carbon steerer tube can take advantage of a TMD. You can also mount it to a gravel suspension fork.
“It’s fit and forget” says Hicks, “if you want the benefit over bumps, with none of the fuss of suspension”.
“We’re very ‘ride it hard and put it away dirty’,” says Hicks. “I love my gravel bike because it’s easy to look after”.
The Gravel TMD is designed with this ethos in mind, Hick says: “It’s all sealed, and it should never need servicing, and if it does, it’s as simple as undoing one Allen bolt, wiping it off and adding grease. We were keen on this lack of need for servicing, and simplicity.”
Will TMDs work for gravel riding?
Tuned mass dampers could make a lot of sense for gravel bikes with a rigid fork. With no suspension movement, a tuned mass damper can reduce the amount of bump force being transmitted through to the rider.
The mass inside the Gravel TMD is 250g – the same as the Rimpact MTB TMD – but the spring rate has been tailored to gravel riding. The range of accelerations experienced on a gravel bike is narrower than mountain biking, so the Gravel TMD’s springs are slightly softer.
Hicks says that speed of the impacts is higher for gravel bikes with a “much spikier force profile as there is no suspension, the tyres are smaller, and bars are narrower”. This makes gravel bikes far less compliant.
We can’t wait to get one on test and see if it really does lead to a smoother ride, better handling, and less fatigue.
The Gravel Tuned Mass Damper is available from Rimpact now for £229.99 / €267.95 / $308.
