Rimpact TMD V2, Chain Damper & MTB Accessories

Rimpact: Damping for drivetrain and front end

Rimpact is a British manufacturer based in Bristol, founded in 2018 by product designer Matt Shearn and known for tyre inserts, the Chain Damper, and the Tuned Mass Damper (TMD). All products share the same goal: to dampen impacts and vibrations before they reach you.

Rimpact started with foam inserts for tubeless tyres. Now, the brand targets two areas that many underestimate: the chain and the steerer tube. According to Rimpact, teams such as Trek Factory Racing, Canyon CLLCTV, and Scott Factory DH ride the TMD V2.

Rimpact Chain Damper or TMD V2: which one is right for you?

Chain Damper – a quieter drivetrain

A suspended chainring that dampens chain slap and feedback from the drivetrain. Result: less noise and more stability at the pedals on rough sections. For direct-mount cranks, 30–36 teeth.

TMD V2 – a quieter front end

A suspended 250 g brass weight inside the steerer tube absorbs vibrations before they reach your hands and arms. Less fatigue and more stability at the handlebars on long descents.

Service kit, trail springs, chainring

Wear and tuning parts for the Chain Damper: service kit with bushings, seals, and elastomers, softer trail springs for hilly terrain, and replacement chainrings with IGUS bushings.

Both can be combined: the Chain Damper calms the drivetrain, while the TMD V2 calms the front end.

How the Rimpact Chain Damper works

On rough trails, the chain slaps uncontrollably – according to Rimpact, the upper chain run reaches up to 8 m per second. This energy results in noise, chain slap, and feedback in the pedals.

With the Chain Damper, the chainring is not rigidly fixed to the crank. It can rotate a few degrees against two springs, while elastomers dampen the return movement. Beyond that, a fixed stop engages: when pedaling, the ring behaves like a standard chainring.

• 7075-T6 aluminium chainring, hard-anodized, with narrow-wide tooth profile
• Mounted on low-friction IGUS sliding bushings, sealed with X-rings
• Approx. 240 g with a 32t ring – according to Rimpact, about 120 g heavier than a standard chainring

The stock springs are tuned for enduro and downhill. If you ride primarily in hilly terrain and pedal a lot, switch to the softer Trail Spring Kit: It shifts the damping range to mid-sized impacts and reduces pedal kickback.

To the Rimpact Chain Damper

Rimpact TMD V2: the Tuned Mass Damper explained

A Tuned Mass Damper is a weight suspended between springs. If an impact hits the bike, the mass moves against the springs and returns the energy with a delay – smoothing out force peaks. The principle is well-known from skyscrapers and Formula 1.

In the TMD V2, a 250 g brass mass hangs between two springs, invisible inside the steerer tube. Elastomer bumpers at the end of the travel catch large impacts; the entire system weighs about 420 g. Rimpact promises a calmer steering feel, more front-wheel grip, and less arm pump. In Rimpact's blind tests with the first TMD, riders were on average about one second per minute faster.

• No adjustment needed: springs and mass are perfectly matched
• Installation with a 4 mm hex key and 10 mm wrench
• For single- and dual-crown forks with aluminium or steel steerer tubes

To the Rimpact TMD V2

Compatibility: Does Rimpact fit my bike?

Chain Damper

Only for direct-mount cranks: Shimano, SRAM 3-Bolt (Eagle), SRAM 8-Bolt (T-Type), Race Face Cinch, and Hope. 30–36 teeth, 11- and 12-speed chains including T-Type. 53.5 mm chainline for Boost and DH.

TMD V2

Aluminium or steel steerer tube, 1 1/8 inch or tapered. Optimised for steerer lengths of 180 mm or more, measured from the bottom of the fork crown; for shorter steerers, compensate with spacers above the stem.

Most chain guides and bashguards work with the Chain Damper; you may need a thin spacer behind the bashguard. Unsure about your crank, tooth count, or steerer tube? Send us the details, and we will check before you order.

Maintenance of the Rimpact Chain Damper

• Clean and re-lubricate as soon as noise or a degradation in performance occurs – maintenance is performed using a 3 mm hex key.
• If the damper squeaks, Rimpact recommends applying a drop of chain oil to the seals.
• If bushings or elastomers are worn, the Chain Damper Service Kithelps: 4 low-friction pressure bushings, 2 X-rings, 1 O-ring, and elastomers, including spares.
• Worn teeth or rock chips? The Rimpact Replacement Chainringcomes with a new IGUS bushing. Replace your chain at the same time, otherwise both will wear out faster.

The TMD V2 requires almost no maintenance: according to Rimpact, the springs never bottom out and rarely need replacement.

Frequently asked questions about Rimpact

What are the benefits of the Rimpact Chain Damper?

The Rimpact Chain Damper dampens chain movement via spring-loaded elements in the chainring. This makes the drivetrain quieter, reduces chain slap, and results in less vibration at the pedals. When pedaling, it behaves like a normal chainring.

What is the difference between Rimpact TMD and TMD V2?

With the first Rimpact TMD, you had to choose between three sets of springs. The TMD V2 features a single, optimised spring with longer travel so the mass reacts faster, and includes elastomer bumpers for large impacts. Additionally, installation has become easier.

Does the Rimpact TMD V2 fit a fork with a carbon steerer?

Rimpact approves the TMD V2 for aluminium or steel steerer tubes, 1 1/8 inch or tapered. Carbon steerers are not included. An ideal steerer length is 180 mm or more.

When do I need the Rimpact Chain Damper Service Kit?

You need the Rimpact Chain Damper Service Kit if the damper makes noise despite cleaning or if the ride feel degrades. It includes pressure bushings, X-rings, an O-ring, and elastomers. If the chainring is worn, you should replace it during the same service.

Is the Rimpact Chain Damper compatible with SRAM Transmission?

Yes. The Rimpact Chain Damper is available with a SRAM 8-Bolt mount for T-Type cranks and works with T-Type Flattop chains. Variants for Shimano Direct Mount, SRAM 3-Bolt, Race Face Cinch, and Hope are also available.

How much weight does Rimpact add to the bike?

The Rimpact TMD V2 weighs about 420 g in total, 250 g of which is the moving mass. The Chain Damper weighs about 240 g with a 32t chainring, which is about 120 g more than a standard chainring.