robikinkela
Active member
Even the new Levo is not free from noise... (min. 23:00)
Avinox M2s rattle
- Thread starter Rob209
- Start date
Seriously, is that a nearly new M2S making that racket?
Man am I losing my mind or did very few reviewers mention the M1 rattle? Is it possible the bikes were so new they never rattled? Or maybe the test motors were ringers, with blueprinted gears so as not to rattle?
That the new M2s is this rattley already, is sort of blowing my mind frankly, and not in a good way.
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Relax man. There’s threads about issues with the gen 5 Bosch as well. The most recent that it “creaks and groans” under power. So should we go around yelling from the mountains that Bosch gen 5s creak under power? No….
There’s a handfull of people with something going on. We don’t truly know what yet. Majority have a silent bike and plenty with serious mileage already.
Oh I'm relaxed, I don't have one or on order. Just interested is all. Frankly, all the top bikes are moving to this motor system so even if I didn't want the motor, in the future I might not have a choice.
There are just a handful (looks to be 3-5) of comments in this thread from people with M2s (or they have a friend) motors that rattle, this is true.
That said, how many >200 mile M2s are even on this forum? Probably less than a dozen total, maybe a lot less. Do you see my point?
Yah, it's too small of a sample size to draw real conclusions for sure. But next year when there are 100+ M2s owners on this very forum with real mileage on their bikes, what are we going to see then? I dunno, but I'm curious to watch this thread.
We should add a poll where select your miles by category and a yes or no to rattle. Then if we have a minority with no rattle AND high mileage, then we need to dwelve in to their rear hub choice, HP or not, etc. Hopefully, it's just a small minority with a rattle, due to a failure of that spring gear thing, and they get warrantied.
Fun stuff.
xtraman122
Well-known member
Man, I couldn’t even tell you if my current bike rattles, I don’t think I’ve ever ridden without headphones in listening to something.
Mate. There are many M2S build threads. Crestline, Pivot, Forbidden, Teewing, Mondraker, Amflow. Just to name a few. No one in those threads has made any comment since April, (release of production M2S) about the M2S rattling. I date searched those threads for the word rattle. It's not there other than to say, "No rattle"
Just my local store is delivering 40 X M2S bikes in the next month. So far they have delivered 20. I am picking mine up tomorrow. Due to this thread, I asked about any complaints. No rattling complaints.
Clearly I accept there is a handful of bikes with an issue. Though I take people who have never posted before, but post only in this thread, just to say their mate has a rattle, with some skepticism.
I personally am not interested in your speculation. I want to hear from verified owners from the build threads about rattle. This is valuable information. People with 2 or 3 posts total, saying they have issues, I am ignoring. People who don't own an M2S. I am ignoring. You people are cluttering this thread with noise, removing any value it has for the actual M2S owners and prospective buyers. So please step away from the keyboard and get a life.
If this is to be a helpful thread to M2S owners like me, and prospective buyers. We want to hear from those who have the issue, and what is being done to resolve it. Joining this forum and making a single post that you have an issue, is not helpful. Follow up. Let us know what is happening. So if we are unfortunate enough to get a M2S with a rattle. We know what can be done, and what to expect.
Thanks.
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You’re kind of proving my point. But then you’re going on multiple threads calling the M2s rattly…
If this becomes many people saying it, then sure call it whatever. But even as you said 3-5 people out of literal hundreds of M2s bikes out there doesn’t make it a rattly motor… when people have an issue you typically hear about it. 500 people aren’t going to come on here to say all good. Like I said, there’s quite a few Bosch gen 5 issue threads too. We don’t draw generalizations on those issues right?
Like I said, I'm just watching the situation. Not making claims that they are ALL rattling at all.
Your point about 500 people with M2S not coming on here to complain when there's not a problem, ignores the fact that most all have very low miles.
Time will tell.
I’d roughly estimate there’s a couple thousand M2s bikes out in the wild right now and quite a few with some solid mileage. If mine rattles I’ll def report it here. My m1 never rattled at all and has some solid hard ridden miles on it. I’m out from surgery for 2 more weeks but have my M2s cresty waiting.
I just wouldn’t freak out from just a few people having an issue. Solid chance some are not even the motor, but time will tell like you said.
If only you were "just watching" ........
Especially when you have no first hand experience to contribute.I own an M1. I cannot hear any discernible noise from it, other than the motor whine when climbing. I will be getting my M2S on the weekend. First test will be a set of stairs that rattled my Shimano EP6 like a bucket of bolts. The EP801 was better. But the M1 on my Amflow was at a point where I didn't hear it. I'm close to 2000km now. It has remained quiet enough that I cannot hear it.
I ordered my M1 about 9 months after the release. Not sure if that helped.
Points of note for my M2S test is I will be running a lower engagement hub. 40T ratchet. I'm also on a high pivot. I also run the tubed Tannus Armour Liners, which in my experience has really dampened vibrations, giving a much quieter ride. And not just from motor rattle, but the reduced ping off all bumps reduces all MTB noise.
Based on the reviews I've read I believe the Avinox to be better/ smoother at applying power than the Gen5s. It certainly looks better.
I just had other priorities for my system but either would be fine. I tried to buy a Rogue before the Wild actually.
100 miles later and still no rattle at all... Just a permanent smile on my face, and often found maniacally laughing at how capable and fun it is
Not going to lie, it is a worry and I am always conscious that it could start being noisy at any time. But I obsess about these kind of things - the slightest noise in my car and I'm taking it apart kind of guy. So believe me I am looking for it, and if it ever starts rattling in the slightest I will update here with as much info as I can.
(approaching 300 miles, PX Pro XL)
This is really unnecessary, why are you so defensive over anything Avinox? Why do you seem to believe there’s a conspiracy afoot from people claiming to be owners out to say a motor rattles? To what end?
Personally I’m somebody who doesn’t give a damn about motor rattles, hence my earlier post suggesting perhaps we worry about it too much. If the motor is working fine mechanically then all good as far as I’m concerned. Microphones are more sensitive than ears, or maybe it’s just mine are shot after years working with fast jets.
You sound like you’re more sensitive to Amflow/Avinox criticism than motor rattle to be honest.
I’ve got more than 2 or 3 posts, but almost unbelievably
I do have a mate with 2 Amflow bikes in the family. He had an M1 which I test rode last year and he’s now gifted it to his son. It was quiet and still is (the bike, not the son…).He also now has a PX Pro (he’s a well heeled power junkie) and that too is rattle free but he’s only done a couple of bigger rides so low miles so far.
Anyway, lighten up, and if you can’t, then maybe take your own sage advice in your last sentence I quoted.
This site has been a wealth of information. It comes from people sharing their experiences. This is an Avinox thread about Motor Rattle in the M2S. Is it too much to ask to not clutter it with speculation so us people who actually need the information, can find it easily ?This is really unnecessary, why are you so defensive over anything Avinox? Why do you seem to believe there’s a conspiracy afoot from people claiming to be owners out to say a motor rattles? To what end?
Personally I’m somebody who doesn’t give a damn about motor rattles, hence my earlier post suggesting perhaps we worry about it too much. If the motor is working fine mechanically then all good as far as I’m concerned. Microphones are more sensitive than ears, or maybe it’s just mine are shot after years working with fast jets.
You sound like you’re more sensitive to Amflow/Avinox criticism than motor rattle to be honest.
I’ve got more than 2 or 3 posts, but almost unbelievably
He also now has a PX Pro (he’s a well heeled power junkie) and that too is rattle free but he’s only done a couple of bigger rides so low miles so far.
Anyway, lighten up, and if you can’t, then maybe take your own sage advice in your last sentence I quoted.
If people want to speculate about the longevity of the M2S motor, then there is a Lounge area to do that. How about we keep the information threads for information ? It's not rocket science.
Where this comes from, is I was trying to find out how many people have actually reported this issue. My LBS wanted to know because they have zero reports. And this thread is so full of crap, it was a PITA to find.
BTW. Maybe @Greg Watts can do a thread summary. Greg would it be possible to extract out who exactly has reported the rattle issue in the M2S motor, in a summary, and the details they have reported ? Also, can you check those reports against duplicate accounts. Thanks.
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That’s not unique to this thread these days, unfortunately…
Whether anybody else is reporting rattle on their particular bike/motor bears no relation to whether anybody else’s will.
Your LBS will no doubt find out in due course from customers whether any of the ones they sold suffer from ‘rattle’, if they’re even bothered, and not from this thread.
my m2s motor has slight backlash noise if you tap the pedals or for example remove the chain and rock the chainring back and fourth - tbh I cannot see how any gearbox which doesn't have a clutch or similar to completely disengage the gears will not have some backlash noise... The extra changes they added to the m2s were around preventing noise from the bouncing affect of the suspension rather than eliminating gear backlash ? - to the theory around the type of rear hub seems to hold true, if you have a really fine engagement rear hub maybe that invokes more pulling on the chain and hence some backlash noise ?.
So the M2S solution is not “disconnect the gears when coasting.” It is more like:
So the M2S solution is not “disconnect the gears when coasting.” It is more like:
- Reduce backlash
Less free movement before one gear tooth hits the next. - Smooth the mesh
Helical gears engage progressively rather than with the more abrupt contact of straight-cut gears. - Keep more tooth contact under reversal/chatter
The “dual-engagement” claim suggests they are trying to stop the gear train unloading and then clacking back onto the opposite tooth face. - Dampen / distribute load better
Compound planetary gearing can spread torque through multiple contact points rather than one harsh impact path.
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Or 5. do it like Bosch:
While on the avinox motor spooling the chainring backwards splays the outer sprag clutch into engaging the large gearwheel and thus make the rattle with the secondary gearwheel, the Bosch Gen 5 sprag clutch layout disengages completely until the gearwheel starts rotating again. The sprag bits basicaly retract a bit away from the axis holding the chainring and hover over it and only touch the inside of the large gearwheel so no matter what direction the chainring goes the sprag clutch won't engage until the gearwheel spins again.
Its explained here shortly: (watch on YT for translation)
While on the avinox motor spooling the chainring backwards splays the outer sprag clutch into engaging the large gearwheel and thus make the rattle with the secondary gearwheel, the Bosch Gen 5 sprag clutch layout disengages completely until the gearwheel starts rotating again. The sprag bits basicaly retract a bit away from the axis holding the chainring and hover over it and only touch the inside of the large gearwheel so no matter what direction the chainring goes the sprag clutch won't engage until the gearwheel spins again.
Its explained here shortly: (watch on YT for translation)
@Greg Watts
Could you please provide a comprehensive summary of all the information regarding rattle and noise issues associated with the Avinox M2S?
Could you please provide a comprehensive summary of all the information regarding rattle and noise issues associated with the Avinox M2S?
Right, BikeBert. You asked for a comprehensive summary, so here's the state of play on the M2S rattle situation - warts, contradictions, and all. Background: The Problem the M2S Was Supposed to Have Solved
The M1 had a well-documented rattle on rough descents - gear backlash causing the internal cogs to clatter when unloaded. Avinox's engineering response was a dual-gear meshing design (a spring-loaded polymer mesh gear taking up the slack) plus helical gears. Critically, note the language Avinox used: the M2S eliminates gear play noise; the M2 merely reduces it. That's a specific claim, and it's now being tested in the real world.
Press vs. Reality: The Divergence Launch reviews were uniformly positive. E-Mountainbike tested one unit to 2,000km+ and reported zero rattling on descents. @slickrock, who tested M2S bikes back-to-back against the M2 at Sea Otter on brutalized test bikes, found the M2S noiseless on chunky downhills while the M2 had "clear rattle." So the fix demonstrably works - on some units.
Then the bikes reached actual owners. What Owners Are Reporting
@Rob209 reported a rattle starting on his second ride, occurring while coasting over rough ground and replicable by pulling the chain slightly - classic gear backlash behaviour.
@EbikeDoctor chimed in with the same issue at just 100km, and noted it was getting louder. @NLScomponents isolated the source by removing the motor entirely and found something loose making a knocking inside - "kind of heavy feeling."
@mastervier on an Amflow PX reported rattle onset at ~900km after 4 weeks of riding, sudden in character - one ride silent, the next rattling.
@GeorgesEBike put numbers to it with a personal rattle ranking from Lake Tahoe riding:
| Motor | Rattle (1-10) |
|---|---|
| Bosch Gen 4 Race | 10/10 |
| Avinox M1 | 6/10 |
| Avinox M2S | 3/10 |
| Bosch Gen 5 | 1/10 |
So even the affected units represent an improvement over M1 - but not the "eliminated" noise that was marketed. What's Actually Failing?
Two hypotheses in the thread: • Hypothesis A (most likely per Occam's Razor): The spring-loaded mesh gear itself has failed or degraded. This would be a warranty-grade sample defect rather than a design flaw.
@Rob209 believes his rattle is pedal kickback noise, indicating the dual mesh has failed - possibly a broken spring or jammed polymer gear. • Hypothesis B (more troubling):
@nowayfra argues the mesh gear is only one of three gear intersections, leaving two others capable of generating rattle. If true, this implies a design limitation rather than a fixable defect - a different category of problem entirely.
@slickrock pushed back hard on this: "the mesh gear was called out by Avinox to explicitly and completely address motor rattle - saying rattling is happening somewhere else is asserting that Avinox has an inadequate design."
Hypothesis A remains the community's working assumption. @emtbeast added an interesting thermal angle: the M2S housing measured 120°C in Velomotion's derating test, which is at the upper limit of Delrin's rated range. Could the polymer mesh gear be deforming under sustained high load? Speculative, but not implausible given engineering first principles - and something your inner Levo suspension engineer will appreciate.
The Marketing Problem @BikeBert noted that Avinox themselves never explicitly claimed the M2S is completely rattle-free, and that most influencers were careful with wording - saying the bike "feels very quiet" rather than definitively rattle-free.
@BikeBert also flagged the comparison table language: M2S = "quietest," Bosch CX Gen 5 = "none." Those are not the same word.
@Bike Gorilla put it more bluntly: reviewers inferred it was sorted, and it's not - Avinox have ploughed significant marketing money into influencers specifically to communicate the silence upgrade, and a clacking motor on descents is a complete turn-off for most riders.
Warranty Status @B Rabbit confirmed the key point: Avinox sees a rattle in the M2S as a warrantable problem.
That's the good news. The bad news is @Rob209 spent two weeks getting stonewalled by his LBS, who told him "it's just free play before the motor kicks in" - a response that suggests either wilful ignorance or a dealer not wanting the paperwork.
@Bike Gorilla advised: don't take no for an answer - stay factual, keep posting publicly, and don't give the dealer room to make you look like an unreasonable customer.
@Heated backed this up: social pressure works, particularly on a new-to-market product where brand reputation is fragile. Bottom Line
The M2S is meaningfully quieter than the M1 - that's not in dispute. But "meaningfully quieter" and "eliminated" are different claims, and some units are clearly failing to deliver even the reduced noise floor. Whether this is a batch QC issue (bad mesh gears), a design limit (other gear stages), or a durability problem (thermal degradation of Delrin under sustained load) is still unresolved.
For you specifically, BikeBert - you're looking at the Crestline RS 181.2 which runs the M2S. Given that you buy based on data rather than vibes, the honest engineering verdict right now is: the fix works when it works, but it's not universally reliable, and no one has yet opened a failed unit to give a root cause. Worth watching another 2-3 months of owner reports before committing.
Will specifically says 'less motor rattle' not no motor rattle
Rob also says 'Virtually Silent' - not silent
I cannot see how it will have zero backlash noise without a clutch to disengage?, mine is virtually silent, I can reproduce some noise by tapping the crank arm whilst holding the bike stationary, but very rarely (if at all) hear anything whilst riding.
I would like it to be absolutely silent in every scenario, but its def 100% better than the M1
Rob also says 'Virtually Silent' - not silent
I cannot see how it will have zero backlash noise without a clutch to disengage?, mine is virtually silent, I can reproduce some noise by tapping the crank arm whilst holding the bike stationary, but very rarely (if at all) hear anything whilst riding.
I would like it to be absolutely silent in every scenario, but its def 100% better than the M1
100 miles later and still no rattle at all... Just a permanent smile on my face, and often found maniacally laughing at how capable and fun it is
Not going to lie, it is a worry and I am always conscious that it could start being noisy at any time. But I obsess about these kind of things - the slightest noise in my car and I'm taking it apart kind of guy. So believe me I am looking for it, and if it ever starts rattling in the slightest I will update here with as much info as I can.
(approaching 300 miles, PX Pro XL)
Super glad you are not experiencing rattle.
Lots of M1 owners also didn't experience any rattles, even though be design all of the M1's should have rattled. Which goes back to the question if the bike/ hub/ rider/ terrain/ or motor manufacturing tolerances are the differentiator.
So here is what I'd ask Avinox owners to do if they don't hear any rattle while riding: Can you induce any rattling on the work stand by just jiggling the cranks fore & aft? Because that might be a better test if we are trying to evaluate this phenomenon. Basically, removing all the other variables.
xtraman122
Well-known member
I'm sure some of the rattles are brakes or other things, cables specifically come to mind, especially with how they switched to the dongle of cables now coming out which I could definitely see leading to connectors being able to rattle against the inside of the frame. But... The one person's video showing it make some kind of noise on a stand just by moving the chain back and forth definitely seemed like it had to be from inside the motor. Not something that would bother me really, but it seems to be concerning to some.
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Yea that one seems odd and obviously not cables/pads.
Just wanted to point out another thing (brake pads w/gustavs) to look for on those guys chasing rattle sounds.
150+ miles, M2s. No rattle. However, my headset is creaking like crazy!. Maybe I need to make a thread about it?
Which bike and which fork do you have exactly?
Crestline plaid. 2027 ZEB. 180mm
Weird you got any rattle at all on a Gen 5, never have myself. It has a mechanism to completely decouple, designed specifically so there is NO rattle at all. Sounds like that was a faulty unit, or something else on the bike.
