Tuned Mass Dampers (TMD) have grown quickly in popularity among gravity-oriented mountain bike riders. With sprung masses that damp vibration before it reaches the rider, they’ve proven effective at reducing fatigue, improving comfort and control, and calming a bike’s handling. Now, Rimpact is bringing the same technology to gravel bikes, with the new TMD Gravel.
Earlier this year, we reported on Rimpact’s TMD V2, an updated version of its TMD that lives inside a suspension fork’s steerer tube. At the time, the brand stated that the TMD V2 was not compatible with gravel bikes, and that a gravel-specific unit was in the works. The TMD Gravel has arrived. Let’s check it out.
A Tuned Mass Damper for Gravel?
If you’ve spent any time riding gravel bikes, then you are already well aware that impacts are common and vibration is pretty much constant. While we can try to manage it with tire volume, tire pressure, compliant handlebars and wheels, cushioned bar tape, and/or gravel suspension forks, the effects of vibration are an ongoing issue for most riders. A Tuned Mass Damper is simply another method for reducing vibration and feedback from rough surfaces like those frequently encountered on gravel bikes.
The small weight, or mass, in the TMD is suspended between two springs, and it damps vibration by responding to and counteracting forces before they reach the rider’s hands. Rimpact says, “Tucked away at the bottom of your fork, TMD is a suspended mass that manages feedback and fatigue: smoothing out rough terrain so you can stay comfortable and ride further.”
Frankly, I think a TMD for gravel sounds like one of the best applications for the technology. Even smooth gravel creates consistent vibration that is readily transmitted through rigid carbon forks and drop bars to a rider’s hands and upper body, and rough gravel is even worse. I’ve experienced enough hand numbness and arm fatigue in my years of gravel riding and racing to welcome any form of relief. I’m definitely interested in trying it, even if it comes with a weight penalty.
Claimed Benefits
- Go Longer: Feedback from the front wheel is managed before it reaches you. Hands, arms, and mind stay fresher for longer.
- Confidence Over Chatter: Reduces unwanted energy felt through the bar, keeping you fresh to take the long route.
- Smooth Is Fast: Reduces hand and arm fatigue, giving you more energy to push your limits.
- Increased Confidence: A calmed front end with less feedback, giving you a confidence-inspiring ride over rough terrain.
- Out of sight, not out of mind: Securely mounts low and out of the way by replacing the flat mount brake adapter on your fork: no interfering with your cockpit setup.
- Easy Setup, No Uncertainty: Designed to excel over varied terrain, no setup or adjustment required.
TMD Gravel Details
The TMD Gravel operates on the same principle and general design as the in-the-steerer-tube TMD V2, but it has been repackaged to mount externally on gravel bikes. Instead of a fork’s steerer tube, the suspended mass — a weight suspended between two springs — is housed in its own tube. This tube is held with brackets and mounts directly to your rigid gravel fork’s flat brake mounts.
Rimpact says the TMD Gravel is designed for use only with flat brake mounts and is compatible with 140mm and 160mm rotors. The TMD mount takes the place of the flat mount adapter with a flippable design to work with both rotor sizes.
The claimed weight of the TMD gravel is 450 grams. Rimpact doesn’t specify the exact weight of the suspended mass, but we’re guessing it’s similar, if not the same as the V2, which uses a 250-gram brass weight.
According to Rimpact, the TMD Gravel “is designed so the springs never use more than 80% of their available travel. By avoiding full compression, spring life is significantly extended, and replacement is rarely required.” Should yours ever wear out, Rimpact sells a full range of replacement parts.
If you use a gravel suspension fork, Rimpact recommends using the TMD V2, which fits inside the fork’s steerer tube. The V2 is compatible with any fork with a 1-1/8th metallic steerer, and is optimized for steerer lengths 180mm or longer.
Pricing and Availability
The TMD Gravel retails for £229.99 and is available now directly from Rimpact.
