Chasing Bike Silence – STFU Chain Damper

Words AJ Barlas
Photos AJ Barlas
Date Jan 26, 2021
Reading time

In the last few years, modern advancements have made our bikes (and hence trails) considerably quieter. Much of the noise came from our drivetrain, but other problem areas have been tackled as well. An example is internal cable routing, which not long ago was causing riders all sorts of headaches. The rattle of the cable inside the frame was often unbearable. One publication tugged on the cables of every test bike, reporting their findings in reviews.

Not everyone is fussy about bike noise, but heaps of riders have gone to great lengths to achieve silence. Moto foam, while mostly to prevent mud build-up in awkward nooks and crannies, can help damp sounds in some situations. Another strategy was wrapping soft velcro or zip ties with long tails around cables to prevent them clanging around. When it came to drivetrains, tighter gearing and short-cage derailleurs were another popular approach, minimizing the amount of chain there is to fly around. I am guilty of trying a bit of everything over the years.

Specialized Stumpjumper Chainstay protector

When Specialized first revealed this lumpy chainstay protector many people sat up and took note.


With each new bike they move the design over but it's main focus is noise.

In 2021, most bikes leave the shop floor set up to be as quiet as possible. In 2018 I was blown away by how quiet the then-new Specialized Stumpjumper was on the trail. The time and effort Specialized spent studying the chain and how it interacts with the chainstay was equally impressive. The bikes were so quiet, the design sparked knockoffs from World Cup pits to home hack jobs on the local trails. Similar stock designs are now showing up on competitors' bikes.

It seems that mountain bike product managers take bike noise seriously and for good reason; a loud bike can seem clapped out or considered cheap if it sounds like a shopping trolly cartwheeling through the bush. And even if a bike is cheap, it shouldn't sound or ride like it.


The fresh STFU Trail chain dampers.

The Quieter Things Get, The More Noise There Is

Before Specialized released the Stumpy, with its odd, lumpy looking chainstay protection, bikes had already grown impressively quiet thanks to clutch derailleurs and narrow-wide, single chainrings. SRAM's push for 1-by drivetrains eliminated the front derailleur and at least one ring, having an incredible effect on the sounds emitted by our bikes. Forgetting to re-engage the clutch of a Shimano derailleur is a stark reminder of what it used to be like, and that's without multiple front rings. I ain't going back there.

Whenever something improves, it shows the faults of other parts. When the drivetrain grew quieter, other noises could be heard. There's a rumour that once Specialized cut chain noise with their lumpy rubber chainstay protector, their riders were left unhappy with the noise coming from, wait for it… the b-tension screw! What next, rubber bumpers on our derailleur hangers? Hmmm…


All of these bits are noise to some riders. Extra pieces to strap to an otherwise (potentially) clean bike. The STFU comes with just the two hoops to slide your chain through, but now additional mount-pieces can be purchased where a better fit is needed.

I Don't Care About My Loud Bike

Some riders don't give a crap about loud bikes. Buy a bike that's equipped with a marvellous modern clutch derailleur, narrow-wide chainring, and plenty of rubber protection to keep things quiet, while protecting the frame, and be done with it. And it's hard to argue with, considering most modern mountain bikes are damn near silent when they leave the shop floor. If you're one of these riders, then additional parts like the STFU aren't for you. But there’s also the issue of not knowing any better which I'm constantly reminded of and was again with the STFU. .

Personally, I can't handle my bike making a racket; the experience is more enjoyable for me when I only hear tires on dirt. But as with the Specialized b-tension rumour, whenever my bike performs better, something else rises to the surface. I'm hooked on how my bike rides, the suspension effortlessly quietening the trail, physically and audibly. But that left me with a new issue; an odd loud clang from the chain connecting with the frame, and sometimes the tire when things got wild.


The reduction in noise on an already quiet bike, has been impressive.


When I saw Kovarik running small sections of P.V.C. pipe on his downhill bikes years ago I was intrigued but at first, the idea seemed a little ridiculous. Wouldn't the chain just rattle in the sections of P.V.C.? Maybe it was for something my mates and I hadn't considered? Considering Karver's aggressive riding style and taste for music, I didn't imagine him caring about a silent bike. Later he was seen with Fox 40 bumpers strapped to the chainstay, which made much more sense. The rubber of the bumpers damps any sound from the chain running through it. Metal music and quiet bikes… who knew?


The larger hoop is the rearmost STFU, with room to work comfortably with our ~500% percent trail bike drivetrains. The smaller hoop goes closer to the chainring, with less range of movement made closer to the chainring.


The chain dampers come at a length that covers a huge amount of bikes. A Stanley knife is used to cut through the firm skeleton, chopping the size down to fit with your bike. They fit most bikes but there are a couple that won't work.

Since the Fox 40 bumpers, Kovarik and his business partner – engineer, Jaan Hurditch – have designed a system that can be fitted to most bikes. Silence is golden – or at least the noise from the rubber of our tires slapping the ground is. But if aesthetics are more important STFU might not be for you.


The chain dampers worked well without the mounts, but for my setup, they helped them stay in position.


If I didn't keep the chainstay protector, they would sit well on the square, alloy tubing. The protector‘s part of the cable routing though so it remains.

I've been running the Trail model of the STFU Chain Damper since the first production run. Following the directions provided, it mounts easily and does what it's tasked with no quibbles. If I take it off, I'm quickly reminded of how the STFU cuts down noise. But most interesting was that it wasn’t just the sounds from the chain connecting with the supplied chainstay protection. The STFU’s restriction on the chain made the bike feel better, cutting down on feedback through the drivetrain when rumbling down a rough trail. With the chain not able to sling around as much, everything feels tighter, similar to running a fresh chain verse a flogged one.


Restricting the movement of the chain is the biggest difference and STFU claim it can prolong your drivetrain's life. I can't confirm that but it certainly feels better when I'm using it, and keeps the bike quieter.

Since using the STFU, I've also noticed and appreciated less wear on my rear rim, which often looked like a stop sign someone had used for target practice. The GeoMetron G1 has improved chainstay protection from the earlier G16 but is still a few years behind industry leaders in this department.

Each chain damper is built around a firm plastic skeleton, providing the rigid structure necessary to keep the damper in shape. The outside is coated with a soft rubber that damps the noise of a chain and prevents excessive movement.

The STFU chain damper does what it says on the box, and while it won't be for everyone, riders keen to silence their drivetrain will appreciate it. For best results you'll want to leave the clutch engaged to prevent the chain from moving around too much on our long chained 500% drivetrains.

The STFU Trail chain damper retails for 34.95 USD.

AJ Barlas

Age: 39
Height: 191cm/6’3"
Weight: 73kg/160lbs
Ape Index: 1.037
Inseam: 32”
Trail on Repeat: Changes as often as my mood.
Current Regular: Every test product spends time on Entrail

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+2 WasatchEnduro JVP Nologo cedrico Shoreboy thaaad
rolly  - Jan. 26, 2021, 6:36 a.m.

Can STFU make something for all those buzzing hubs out there? (I can dream, can't I?)  I know some people LOVE them, but I don't get it.  Unless we're in a bike park or jump park, having the pawl buzz takes the beauty out of the natural environment for me.


+2 Grif Moto Master Shoreboy Zero-cool WasatchEnduro Nologo
KavuRider  - Jan. 26, 2021, 7:45 a.m.

And on the other side, I love the sound of buzzy hubs.  Any other creak or noise from my bike annoys me, but a hub buzzing along is music to my ears.

To each their own I guess!


+2 WasatchEnduro Nologo
AJ Barlas  - Jan. 26, 2021, 8:51 a.m.

This is a perfect example of the noise some riders don't mind (and even enjoy), and others despise. Thanks, fellas. 

I've gone back and forth over the years and for some reason am more open to a loud hub on my dirt jumper, but not so much on my trail bike. A bit of light grease often helps quiet it down, Rolly. Be careful not to use too much though (or too thick of a grease).


+1 goose8
Cooper Quinn  - Jan. 26, 2021, 11:53 a.m.

Its great for gauging speed on a DJ bike - which can otherwise be challenging at times. 

This is part of why some BMX racers won't run Onyx or other silent hubs.


+1 Pete Roggeman
AJ Barlas  - Jan. 26, 2021, 12:02 p.m.

Interesting. I've never considered that but can see how. A friend used to despise riding in a full face but couldn't work out why. After some thought and further testing, he realized it was because the shelter from the wind on the face and by his ears made it feel like he was riding slower. So he'd go quicker as a result but ended up in trouble more often than not. It just wigged him out.


+1 KavuRider
Cooper Quinn  - Jan. 26, 2021, 12:27 p.m.

Yup. If you throw goggles and full face on, you've limited some of the biggest inputs to your brain for its 'how fast am I going' computations. This is especially true on bigger/wider/smoother trails, as there's less other sensory input. Think Dirt Merchant vs... I dunno. Something narrower with a rough surface and trees everywhere. Schleyer. 

On Schleyer you've got lots of other data inputs; banging into rocks, passing trees/bushes, etc. On Dirt Merchant you've got a smooth trail and the closest tree is 30' away. That wind feel/noise (and hub noise?) is suddenly a much more primary input.

+1 AJ Barlas
KavuRider  - Jan. 27, 2021, 7:41 a.m.

You just nailed the reason why I don't like riding with a full face on (even though I should).  I couldn't put my finger on it. But yes, being cut off from that sensory input freaks me out. 

Never thought if it like that!

+1 JVP Nologo Shoreboy
WasatchEnduro  - Jan. 26, 2021, 9:49 a.m.

I'm with you, rolly.  After a couple of decades on normal/crappy hubs I built a wheel with a Project321 quiet pawl hub.  High engagement and nice and (almost) silent.  Might try Onyz next but this P321/LB carbon rear wheel refuses to die after 3 1/2 years of trail riding in the west and hundreds of cased landings.

My buddy built a wheelset on King hubs and I thought they would be obnoxious but I like them the best of the 'noisy' hubs.  I9s are like the guy with the anti-muffler on his truck just riding around looking for attention... as much as I'd love a wheel built with their lovely ano spokes one day.


+1 WasatchEnduro
JVP  - Jan. 26, 2021, 11:53 a.m.

I'm pretty close to building up a new wheelset with quiet hubs. With a Mezzer and some mastic tape work on the CS my Patrol is so damn quiet except the old Hope hub. I want to go to that special place on rides and meditate on the sound of my side knobs ripping through duff and gripping loam!

Just need to decide WTB KOM metals or WAO plastics. Pros and cons.


Michael  - Jan. 26, 2021, 5:47 p.m.

I run a buzzy hub to alert this new insane population of Shore hikers and lame riders from Ontario. So is the Shore finally dead? Sad to say yes it's an old beaten rug, tracks on the map are mostly destroyed and not fun to ride anymore . All the hidden gems get found and chopped.


Ryan Walters  - Jan. 26, 2021, 6:44 p.m.

DT star ratchet hubs. You're welcome.


+1 WasatchEnduro
jdt  - Jan. 26, 2021, 8:58 a.m.

A few questions.

  1. It seems these will fit some stays better than others, namely those with a flatter top surface or rectangular or box cross section. How well might this work for more sculpted or even (gasp) tubular stays? I note the "foot" at the bottom of the stack. Is it configured in a manner (shape and density) that it will fit well to most shapes?
  2. You indicate that these must be cut to length. Certainly that is something you need to get right the first time. Is it easy to measure in that respect?
  3. I assume the system cannot be transferred to another bike unless the stays are very similar. Yes?
  4. How is the long-term attachment? Has it stayed in place or has any wiggle crept in?
  5. If wiggle does creep in, can one simply reapply zip ties?


+3 STFU Bike Cam McRae jdt
WasatchEnduro  - Jan. 26, 2021, 9:41 a.m.

I've been on this a while so here's some rando's experience:

1. I'm running this on my alu ripmo and couldn't secure the forward mount so just run the rear.  So yes, chainstay shape can have an affect (or I'm a hack).

2. I think the instructions say to err on the cautious side. Once you cinch it down you may find you cut one too many notches off (ask me how i know).

3. probably (stays and/or gearing) but I like how affordable this is.

4. snug those zip ties again after a ride or two then you're good. 

5. yes.


+1 STFU Bike
AndrewR  - Jan. 26, 2021, 11:32 a.m.


1. 2020 Norco Sight: no issues fitting it but a rounded square chain stay and I also fitted it over my extra strip of 2228 tape (or RideWrap chain tape). Also have Ridewrap clear on the chain stay.

2. Yes and quite precise obviously pays off. I took the view that the master link I was removing was the one that I would use multiple times during the measuring and checking phase (I think I threaded my chain maybe 6-8 times - cannot exactly recall but it is lots) so that I was able to 'pedal' and shift gears to check upper and lower tolerances. Then once I was finally totally happy with the STFU position I fitted a new master link for riding.

3. If the gap is closer you could re-trim it shorter to fit if you go from bike to bike. But I doubt you can glue extra sections on if you trim too short (if you have even kept them) so see 2. above about carefully sizing before you commit to the final length/ height.

4. Awesome. Two large zip ties per STFU piece. Give it a good pull with flat nose pliers to cinch them up nice and tight. Mine do not move at all. 

5. Not had any wiggle but I check it every time I do a full chain clean. Appears to be bomber and wearing well for 800+ km of Sea to Sky trail riding.

The STFU really does quieten the drive train down and totally worth the pfaff of fitting it. Getting another set for my Optic. Also doesn't appear to attract mud either which is a good thing.


+1 WasatchEnduro
STFU Bike  - Jan. 26, 2021, 11:51 a.m.

Thanks for the questions!

1. We include two different shaped end caps with the TRAIL units so they fit rounded stays, one has a 15mm diameter to work with tubular stays like chromag hardtails etc. and the other has a 35mm effective diameter  to work with slightly rounded stays. We have the end cap sets available separately too so anyone who purchased before they were included can get them for the price of shipping. 

2. We have instructions online but its essentially as easy as shifting into hardest gear, measuring to the underside of your chain at installation point and cutting at the measurement point provided on the chain dampers. Clearance has been factored in but its definitely a measure twice, cut once deal.

3. Thats correct, once cut its difficult to make the damper units longer although it is possible to join the cut piece back on with a couple of cable ties.   

4/5. We found that most cable ties tend to stretch a little after the first few rides, especially in the sun and even the UV stabilized ones but cheap ones stretch even more. For this reason its important to leave a little length on the cable ties so you can tension them up after the first couple of rides. After that they are good to go. We are testing some plastic coated stainless steel cable ties that shouldn't need to be tensioned again, its just a real challenge trying to fit cable ties on the packaging without blowing out the size, which is why we currently don't provide them.


goose8  - April 11, 2021, 6:30 p.m.

I know it's been a while since this review, but I have a question about using different cassettes/chainrings with the STFU system. Right now I'm running a cassette that goes up to a 42t mated to a 26t oval front ring. Waiting in the wings I have a 46t cassette and a 28t oval front ring as backup. What are the chances that the STFU would play nicely with both of these setups? Should I make the cuts based on the larger cassette and chainring to be safe? Love to hear your thoughts if you happen to be keeping tabs on this board. Cheers!


+2 WasatchEnduro jdt
AJ Barlas  - Jan. 26, 2021, 12:18 p.m.

It seems the guys who have already replied have you covered JDT. For a visual of the two different mounts that can be added, check the image with the caption starting; "All of these bits are noise to some riders." It shows the uncut modules as well as four mounts—two different frame interfaces—available.


+6 Pepe Jerry Willows Shoreboy Cr4w Sandy James Oates Nologo
Dave Smith  - Jan. 26, 2021, 9:05 a.m.

The thought of zap strapping a cheap hunk of 3d printed plastic to my multi-thousand dollar plastic bike when the company could have just put on a 10¢ piece of rubber really bothers me.


+3 Cooper Quinn Dave Smith WasatchEnduro Timer Nologo
Perry Schebel  - Jan. 26, 2021, 9:56 a.m.

ditto. these are an affront to my minimalist sense of aesthetics.


+3 Dave Smith WasatchEnduro Nologo
Cooper Quinn  - Jan. 26, 2021, 12:13 p.m.

They're an affront to aesthetics, period. 

But, I do not miss the days of my M1 sounding like a filing cabinet full of loose wrenches rolling down the stairs. Its no wonder Kovarik is the man behind that after his years on that bike. 

I'm with Dave here.


+1 Timer
Dave Smith  - Jan. 26, 2021, 12:21 p.m.

The ghost of Dieter Rams should be haunting 98% of the designers in the bike industry


+1 AJ Barlas
IslandLife  - Jan. 26, 2021, 2:29 p.m.

Me too, I bought the VHS tape... just put it on last night... riding next on Friday, will see how it works.


+2 Cooper Quinn cedrico
STFU Bike  - Jan. 26, 2021, 11:59 a.m.

They're not everyone's cup of tea in the looks department. We prefer function over form though and you can't see your drivetrain once riding your bike but you can definitely hear it on most.

The units AJ tested were pre-production samples that are a bit rough compared to the finished units, they're injection molded ABS plastic with a TPU overmold though, not 3D printed although we did do a bunch of prototyping with 3D prints. 

The production end caps have a nice little hexagonal surface finish where they interface with the stays too for added grip that's not on the samples AJ got. Cheers for checking them out. :)


AJ Barlas  - Jan. 26, 2021, 12:12 p.m.

As STFU said, they're not everyone's cup of tea but they work. So if a quiet bike is something people are after, this will achieve that more than simply relying on the stock protection. It's not just the sound that they cut down on either, and limiting the space a chain can move has an effect on the feel of the bike. It's not massive, but I found it noticeable. Some won't notice the difference of a new chain, others will. That's a close comparison to the difference felt on the trail. 

I'm all for minimalism where suitable. Pole bikes are a big proponent of it but tbh, I find the quality of the finished product lacking and clunky as a result. Sometimes a bit extra goes a long way to cleaning up the ride experience and that's what these can do. 

Each to their own, though.


Zayphod  - Jan. 26, 2021, 10:32 a.m.

It baffles me that Chaintamer didn't get the attention it deserves for being the first one to offer such product, but this rather ugly take on it did.


AndrewR  - Jan. 26, 2021, 11:33 a.m.

Tell me who designed and marketed chaintamer? That's essentially your answer. 

Kovarik has a huge following so anything he does attracts some attention.


+1 AJ Barlas
Skeen  - Jan. 26, 2021, 11:24 a.m.

I won’t be trying this piece of tech out, but still found it to be an interesting read and glad to know they work as intended. As long as my bike isn’t creaking, grinding or making any sounds that indicate a mechanical issue I am good to go.


AJ Barlas  - Jan. 26, 2021, 12:15 p.m.

Thanks Skeen! Glad you know what you're after and are open to others being different. Can't argue with that.

+4 STFU Bike Andeh AJ Barlas Pete Roggeman
Cam McRae  - Jan. 26, 2021, 12:39 p.m.

I had no interest in this system before reading AJ's article. And damn you AJ! Now I do!


fartymarty  - Jan. 26, 2021, 1:28 p.m.

It's like the crack in the windscreen (windshield for those in North America) - once you've seen it you can't unsee it. 

I'm now going to be listening out for my chain every time I ride.

Edit - Just bought a set as the chain slap was getting too annoying.


+5 Dogl0rd AndrewR AJ Barlas Pete Roggeman Squint
Andeh  - Jan. 26, 2021, 3:28 p.m.

NSMB has been responsible for more than one purchase of things I previously didn't know I needed.


cheapondirt  - Jan. 26, 2021, 8:13 p.m.

When I first heard about these I was really interested, but then I got a Durolux and now that's about all I hear. My breathing on the ups, and fork damper on the downs. Got to figure out a way to make the Durolux louder when climbing.


Alex Hennrich  - Jan. 27, 2021, 6:11 a.m.

Hey, nice article, was also thinking about either the good ol´2228 with DIY ridges or the VHS tape. Now these fugly thingies seem like a neat solution. What´s the tolerance for changing chainring sizes? If I go from a 32 to a 34 or 30, will they still fit or is it basically one length per chainring size (which would be a bummer)?



AJ Barlas  - Jan. 27, 2021, 8:48 a.m.

Great question, Alex. I don't change ring sizes so I can't answer confidently but the front mount has some wiggle room. The rear is much tighter at each end of the cassette and increasing the max size rear cog would likely introduce greater problems than with the front.


Alex Hennrich  - Jan. 28, 2021, 6:40 a.m.

Thanks... what about oval rings? Do you think there´d be a problem going from "old eagle" (50T) to "new eagle" (52T)?


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