Rimpact sent out a press release about their new chain damper which looked a lot like some other things I had tested, so I asked to get one. They obliged and answered some of my questions about the product. Read their press release info below followed by my first not-on-the-bike-yet impressions with more to come.
Featuring an Integrated Chain Ring Design
By integrating the chain ring directly into the Chain Damper, we've achieved an incredibly stiff and creak-free design. The crank interface is built seamlessly into the front plate of the damper, allowing us to create the best possible product without being limited by the traditional BCD chain ring design. This design ensures maximum durability and performance by eliminating unnecessary noise or flex.
The Chain Damper isolates the rider from spikes in chain energy, reducing drivetrain feedback. Bringing the chain under control, the rider is more closely connected to subtle suspension action. The Chain Damper is engineered to smooth out peak chain forces by capturing it within a precisely calculated angle of rotation.
Long Service Intervals - Easy Service Process
The Chain Damper has been designed to survive UK winters. You won't need to service it as often as some high end products thanks to its triple sealed casing that features a "labyrinth" design to minimize any water and dirt ingress. When it does come to servicing your Chain Damper, all you will need is a 3mm Allen key and some grease.
A chain weighs around 260 grams on average and the top part of your chain, (the length between the chain ring and cassette) can move at 8 meters per second, completely uncontrolled. Clutch derailleurs offer some amount of control to the lower part of your chain but the top remains free to flail wildly.
Here at Rimpact, we think the significant effect of this uncontrolled chain energy plays a bigger part in unwanted ride characteristics than other sources of negative drivetrain feedback.
We've designed a device that can capture this energy momentarily, smoothing out the peak energy spike that usually translates to this significant drivetrain feedback. By controlling the chain's energy spikes, the Chain Damper creates a silent and calmed ride characteristic that lets the rider focus in on subtle suspension movements and the sound of tyres gripping the dirt. Ultimately a more confidence inspiring ride.
The Chain Damper is available in 30t-36t chain ring sizes, is 11/12 speed compatible and is also suitable for use with T-type drivetrains. The first batch is 32t and 36t ring sizes for Shimano direct mount, SRAM 3 bolt & 8 bolt cranks. Other crank options are in production and an E-bike option is also on the way.
Price - 279.99 GBP / 324.99 EUR / 374.99 USD
Available through https://www.rimpactmtb.com/ or through these distributors today! With more coming soon!
USA - bti-usa.com
Canada - cycolo.com
Australia - bikesportz.com.au
New Zealand - swiftdistribution.co.nz
Norway - Plan A Sports AS
Mexico - crossmountain.mx
Spain - bikecomp.com
FIRST ROBOTIC IMPRESSIONS
Amazing! Loving these tests! Thank you for your service Captain Robot 🫡
I was just checking that out, looks interesting. A bit cheaper than an O-chain plus chainring. Is it noticeably slimmer? My O-chain has very minimal clearance to my chain guide backplate. Did you ask about replacement chainring cost? I don't see anything in their FAQs.
Great question! Replacement chainring cost was one of my first thoughts, too, because they look proprietary and potentially cost a lot of $$$. Here's what Matt from Rimpact had to say:
"Replacement chainrings are £69.99 GBP, 84.99 EUR and 89.99 USD and that includes a new bushing for the device to keep everything running sweet. The ring is type 3 hard anodised alu 7075, which is approximately 5x thicker than the regular type 2 anodizing you'll see on the coloured chainrings on the market. This should lead to a much more durable and longer lasting ring compared to other colourful options."
$90 US isn't cheap, but it's not terrible. For comparison, that's a little less than a $100 5-Dev direct mount chainring, and a little more than an $80 Wolf Tooth. Also worth noting that the new chain damper is only available in 32 and 36t sizes for the time being, with 34 and 30t options coming later. I'm guessing the two sizes they chose for the short-term are targeted at DH bikes (36t) and winch and plummet bikes (32t). 30 tooth will be a big advantage for Rimpact when they become available, as Ochain's don't officially fit 30-tooth chainrings and I know lotsa people running them in hilly places.
Haven't mounted it yet so I can't say for certain. I went with the 36 tooth option, so I'm waiting on a new 36 tooth chainguide before I can mount it. My current MRP guide maxes out at 34. In the meantime, I'll just say that the packaging between the mechanism and your chainguide's backplate looks comparable to what you've experienced on your Ochain. She thick.![]()
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I can't actually describe it well right now because I've caught a cold and my brain is in "suffer through work mode" but...
...I think you could call this technology a "Tuned Mass Stamper."
Blah, blah, blah, hahaha. But also...kind of? My brain is telling me it smooths the motion of the chain in a similar way to how a TMD can smooth the chaos of a fork (or other part). It doesn't stop it but the tuned portion allows the weight and the attachment to the bike to damp the chain's motion.
I really posted just to say "Tuned Mass Stamper." Carry on.
Edit 3 hours later: My sorta ill brain just told me "Tuned Stamp Damper." That's way better.
Over.
Here's more from Matt at Rimpact on how/why it works:
The next version could have some kind of locking mechanism, to ensure no sloppiness/squishiness for climbing (I don't know how stiff the springs are, but I can imagine they compress under strong pedaling loads at least...?)
Trying to visualize myself gliding through the woods with my e13 hub, rimpact spider, and STFUs strapped to my 30a durometer wavy chainstay protector...
Ochain N (non adjustable) says it works with 30t fwiw
Good catch!
I've just fitted mine, so far so good. Having never ridden OChain or this before its a strange feeling.
Running a low engagement hub also.
Proper test on the weekend at my local DH park.
How far do you need to pedal for the engagement to hit without with your hub, just the rimpact.
the engagement is instant, you get 8.6 degrees of 'float' on the crank.
OChain have the option of 3,6,9,12 degrees of float.
Let us know how you get along with it!
So that effectively means if you're careful enough with building a contraption similar to Kovarik's STFU you'll get all the benefits for a fraction of a price?
I don't think that's what Matt is claiming. The Rimpact damper is supposed to act like a chain tensioner for the top of your chain. As a bad example, imagine getting rid of your derailleur cage as a tensioner and just using STFU on the bottom of the drivetrain. A tensioner does something special for chain tension that STFU can't do. Both of them acting together could be sweet, though.
The best way I could describe it is imagine the chain is flapping about as you go over rough ground and growing as the bike goes through the travel, the device allows the chainring to rotate or 'float' to reduce the energy felt through the pedals.
I've not ridden an OChin but I understand it does a very similar thing.
Full test over the weekend for me.
Full day DH bike park testing at Danny Hart's Descent Bike Park in the soaking wet.
Very impressed, the bike (Privateer 161) now feels alive and very 'poppy' Good under braking and so settled on the rough stuff.
A slight squeak but Rimpact advise this is fixed with chain lube.
It has the same function as the ochain but they are trying to convince everyone that they have invented something new and groundbreaking because they are calling it the chain damper, doing what we have all discussed here that the ochain does. I welcome more actors in the pedal kickback/chaindamping but I hope the worst on this pack of liars.
"rimpactmtb two brakes may look the same but not function the same. There is little overlap in this design compared to Ochain."
Any update on actual performance or feel on the trail? Trying to decide between ochain and this for the season.
Thx
Full review coming soon, but I just received an updated version of the Rimpact with a lighter set of springs and will report back after my first ride on Friday. The sealing is a million times better on the Rimpact damper (they're from the UK) than on the Ochain, so that's in the plus camp. I didn't love the stiffer springs on the Rimpact, so I'm curious to try the softer springs. My understanding is that new Rimpact Chain Dampers will now ship with both the softer and stiffer springs for both types of riders. Full review will explain more about who/where/what will benefit from each spring type.
Sounds good! Anxiously awaiting the report.
have been on the fence with the o-Chain all offseason mainly due to the maintenance (frequency & Complexity). If I can get a full season out of the rimpact chain damper and it is comparable to the o-chain in performance I am pretty sure I am in. Going on the DH bikes, so pedal performance/feel is not really on the list of concerns for me.
Cheers
Is this and O-chain, only beneficial for longer travel bikes? Does it require a certain type of terrain (DH/Enduro type runs) to really feel the benefit? Are there specific suspension layouts that its more effective for? I'm not planning to run out and buy one for my 140mm trail bike at the moment, just curious if they have a universal benefit or a more terrain/bike specific one.
I would recommend watching this video from last summer.
https://www.vitalmtb.com/features/can-pedal-kickback-denier-see-light
Ochain has advantages on any travel bike. But the negative is that you are introducing play at your cranks so on shorter travel bikes it can be weird to have play in tight uphill tech scenarios.
My first ride around parking lot on Rimpact damper was really weird, like TeamRobot says the lighter spring could be the answer to fix the issue. It’s kind of mind blowing that they would initially ship them that way in my opinion. Basically the springs were so stiff that when the cranks get to 6 and 12 o’clock the chainring would rotate forward then you’d take slack up then it would spring forward. Very weird sensation that I’ve never had from ochain.
What is great about ochain is the ability to lock it out, 4,6,9, 12 degree options of free play. Just my 2 cents.
I thought this video was super interesting. It's The Rimpact owner Matt Shearn talking about the Rimpact Chain Damper, what it's doing, and what it's not doing.
Hey all – thanks for the great discussion and thoughtful feedback, it’s been great to follow.
Just to jump in with some info from our side:
The Chain Damper was originally developed for aggressive DH and winch-and-plummet style Enduro riding—especially the kind we do here in the UK with steep climbs and even steeper descents. The standard spring setup is tuned to perform best when descending hard, where the damper really shines and this is why you'll see the unit on a number of WC bikes this season.
That said, we totally get that not everyone rides the same terrain or prioritizes the same feel. In response to rider feedback, we’ve recently released a Trail Spring Kit which are the springs Jason has in his updated unit for testing . This softer spring option shifts the damping effect more toward mid-range impacts, softening the pedaling sensation and creating a more natural climbing and rolling feel—ideal for more undulating trails or lighter trail bikes.
The stock setup can definitely feel a bit odd during car park tests or when pedalling lightly on flat ground—that’s completely expected. The Chain Damper isn’t designed to feel great in a car park like most DH and Enduro bikes. However we've found riders adapt to the pedalling sensation after just a few rides—and in our opinion the benefits when descending is a trade-off well worth making.
If anyone has any other questions, feel free to drop us a message here or directly.
Thanks
Matt
Founder of Rimpact Components
Ive been riding one 6 months, the initial feel is strange but soon get used to it. No issues on reliability, and its been muddy over winter in the UK.
Bike feels really active with it fitted, nice and quiet.
Chain ring is showing no signs or wear.
Great find! I actually learned abut RimPact through the Down Time Podcast when they were talking about the TMD steertube device.
Your semantic ire should be aimed at the pedal kickback club, they’re like the cops who maybe touch fentanyl and have panic attacks. The math just doesn’t seem to be there for pedal kickback, but half a pound of chain banging around back there does. Credit to Rimpact for calling it what it is.
Call it Bounce Gremlin Trap for all I care: these things make the ride faster, smoother, and quieter. All for it!
Glad to see others don't buy into the whole "pedal kickback" thing. Personally I believe it's down to unpredictable anti-rise causing the suspension to firm up, which you'll definitely feel more through the pedals. Having tried a bike with an O-chain, I still felt harshness through my feet, it seems to be solving a problem that doesn't exist. Now, stopping the chain from flapping around like the rimpact claims to, is a really interesting prospect!
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