Amflow PL Carbon owners, check your seat tube for cracks!

[Astro66]

And some fanboys call it "professional attitude".

Mate. Saying you don't offer warranty on international purchases, then following through and not offering the warranty when someone does exactly that, is a "Professional Attitude". Offering the warranty to you would be unprofessional to the dealer networks and thousands of other buyers who bought through the correct network.

Do what you say. Say what you do. Professionalism.

Knowing you shouldn't get warranty, then misrepresenting Amflow, to try and bully them into giving the warranty, is Unprofessional. I know you'll never see it this way. It goes with the attitude.

 

[Balduin]

Behind Amflow stands the tech giant DJI. Unfortunately, this is clearly evident in their customer service structure.
While established bicycle brands often handle known manufacturing defects in a flexible and straightforward manner—and replace the product without any hassle—Amflow’s customer service sometimes demands absurd proof when a warranty claim is filed.
As a buyer, that definitely puts me off.

 

[Joecrow]

der Kundendienst von Amflow manchmal absurde Beweise, wenn ein Garantieanspruch geltend gemacht wird.

Zum Beispiel? Ich würde gerne einen Vergleich mit einer deutschen Fahrradmarke anstellen.
(Such as? I'm interested to compare against a German bike brand.)

 

[Moderator]

ok, lets stop padding the thread out with repeated discussions on warranties and keep it to discussing any potential seat tube issues, possible frame batches and any solutions - or otherwise.

As a reminder, please post in English on the forum.

Thanks.

 

[Balduin]

Zum Beispiel? Ich würde gerne einen Vergleich mit einer deutschen Fahrradmarke anstellen.
(Such as? I'm interested to compare against a German bike brand.)

Example? I'll give you one:
Specialized once had a problem with Brose where the belt kept breaking.
Specialized simply extended the warranty for that model line from two to four years.

 

[Joecrow]

Example? I'll give you one:
Specialized once had a problem with Brose where the belt kept breaking.
Specialized simply extended the warranty for that model line from two to four years.

I was looking for an example of the quote, if my translation is correct:-
"Amflow's customer service sometimes demands absurd amounts of evidence when a warranty claim is made."

 

[Balduin]

I gave you an example of how someone else acts; at a certain point, you have to think for yourself.

 

[Joecrow]

I gave you an example of how someone else acts; at a certain point, you have to think for yourself.

So is it fair enough to say that despite your claim about Amflow customer service you can't actually come up with an example!

 

[insplean]

ok, lets stop padding the thread out with repeated discussions on warranties and keep it to discussing any potential seat tube issues, possible frame batches and any solutions - or otherwise.

As a reminder, please post in English on the forum.

Thanks.

I think it’s just important for them to argue)

 

[skizzian]

I think the problem also lies in the construction—the seam where the carbon layers meet runs through this area. The photo shows the spot after the paint and clear coat have been removed.

View attachment 187544

the seam is a small 'stress raiser' but I'd imagine most carbon frames would have the tool close in that axis (it's the lay up underneath that counts mainly).
the most obvious stress is the end of the inserted dropper post - pivoting 240mm from the seat clamp, it's a large moment, perhaps the diameter of the seatpost tube is too large, allowing that movement - does the seatpost drop in or need a twist?
Whatever has happened (there are many places manufacturing could fail) it points to poor QC.

 

[insplean]

the seam is a small 'stress raiser' but I'd imagine most carbon frames would have the tool close in that axis (it's the lay up underneath that counts mainly).
the most obvious stress is the end of the inserted dropper post - pivoting 240mm from the seat clamp, it's a large moment, perhaps the diameter of the seatpost tube is too large, allowing that movement - does the seatpost drop in or need a twist?
Whatever has happened (there are many places manufacturing could fail) it points to poor QC.

I measured the length of the dropper post inside the frame today and noticed something very interesting: the center of the crack is quite far from the bottom of the dropper. This means the issue definitely isn't caused by pressure from the end of the post itself. Also, more than ten riders have already encountered this problem. This leads me to hypothesize that the issue isn't due to poor quality control or manufacturing oversight, but rather a defective mold. A subtle protrusion might have formed in that spot, creating a stress concentration point. Of course, they really should have tested units produced from that mold, but no one is going to tell us the truth (I’d appreciate any information at all from Amflow, though I doubt they’ll even reply).

 

[skizzian]

I measured the length of the dropper post inside the frame today and noticed something very interesting: the center of the crack is quite far from the bottom of the dropper. This means the issue definitely isn't caused by pressure from the end of the post itself. Also, more than ten riders have already encountered this problem. This leads me to hypothesize that the issue isn't due to poor quality control or manufacturing oversight, but rather a defective mold. A subtle protrusion might have formed in that spot, creating a stress concentration point. Of course, they really should have tested units produced from that mold, but no one is going to tell us the truth (I’d appreciate any information at all from Amflow, though I doubt they’ll even reply).

I still think it's more likely to be poor lay up or vacuum or oven
also the end of the crack may not be where it propagated from; but you have it in your hand and have seen it in the frame so you will have a better feel for what's going on than me.
the carbon layers shouldn't 'meet' in that area, there should be different shape, size and types of weaves overlayed to give strength in the required directions. The mould gives a nice skin to the gel coat - the inflatable form inside could also have been off - that would constitute part of the mould, but any voids or inclusions would be hidden.
having said that I have a D shape 'carbon' Giant seat post that keeps snapping - it's not a layup at all - looks like a short strand injection - but I doubt that would be the case here

 

[insplean]

I still think it's more likely to be poor lay up or vacuum or oven
also the end of the crack may not be where it propagated from; but you have it in your hand and have seen it in the frame so you will have a better feel for what's going on than me.
the carbon layers shouldn't 'meet' in that area, there should be different shape, size and types of weaves overlayed to give strength in the required directions. The mould gives a nice skin to the gel coat - the inflatable form inside could also have been off - that would constitute part of the mould, but any voids or inclusions would be hidden.
having said that I have a D shape 'carbon' Giant seat post that keeps snapping - it's not a layup at all - looks like a short strand injection - but I doubt that would be the case here

You are generally right that the problem lies in the manufacturing process. I don't think the issue is specifically with the carbon layup; there are two reasons for this. First, it’s a widespread problem, but it seems linked to a specific batch or production line rather than affecting random frames. Second, I’ve ridden budget Chinese frames—and know others who have—and while it’s unlikely they use different types of carbon for those, I’ve never seen this kind of problem. The key factor is that the stress point should be near the frame's lower link—my dropper post extends quite far down. Yet, for some reason, the crack spreads across the middle section, with its center roughly beneath the yoke. Furthermore, the crack flexes when I press down on the saddle. This implies that, for some reason, the pressure is concentrated there, even though the load should be focused at the bottom of the seatpost.

 

[insplean]

I still think it's more likely to be poor lay up or vacuum or oven
also the end of the crack may not be where it propagated from; but you have it in your hand and have seen it in the frame so you will have a better feel for what's going on than me.
the carbon layers shouldn't 'meet' in that area, there should be different shape, size and types of weaves overlayed to give strength in the required directions. The mould gives a nice skin to the gel coat - the inflatable form inside could also have been off - that would constitute part of the mould, but any voids or inclusions would be hidden.
having said that I have a D shape 'carbon' Giant seat post that keeps snapping - it's not a layup at all - looks like a short strand injection - but I doubt that would be the case here

My dropper is positioned roughly as shown in the Amflow diagram; I’ve marked the location of the rubber component in orange.
At the same time, the crack opens up starting from its midpoint—meaning that, for some reason, the primary point of stress is located precisely there.

 

[Gauss Guzzler]

Yes, it has nothing to do with the seatpost. You cannot force a perfectly straight crack thru a properly made carbon structure unless the structure has a perfectly straight flaw in the ply stack. There are only 2 possible explanations: either the plies were misshaped/misaligned such that inadequate overlap was achieved at the seam, or the pressure bladder failed to properly compress this region, leaving air voids between layers.

 

[Kramer]

It would seem to be a manufacturing defect, and IMO it’s poor that Avinox aren’t standing behind their product, no matter how it reached the owner.

 

[Ndanger]

the carbon layers shouldn't 'meet' in that area,

Correct, am I seeing the Crack is linear and possibly at the center of the mould halves, could the significant layers be placed on each half of the mould and the Crack is weakness at the area both halves meet.

 

[skizzian]

Correct, am I seeing the Crack is linear and possibly at the center of the mould halves, could the significant layers be placed on each half of the mould and the Crack is weakness at the area both halves meet.

it definitely could be - would 100% be the wrong way of doing it
possible Friday afternoon apprentice job...

 

[insplean]

Correct, am I seeing the Crack is linear and possibly at the center of the mould halves

Yes, that's true. The photo (not mine) shows the layers after removing the paint.

 

[insplean]

could the significant layers be placed on each half of the mould and the Crack is weakness at the area both halves meet.

I'm not sure. But the crack starts where there shouldn't be a stress point—mine is located below the crack. But if the crack has appeared and is bulging under load, and the dropper post is relatively rigid, then there's clearly a problem with the seat tube itself.

 

[kla456]

it definitely could be - would 100% be the wrong way of doing it
possible Friday afternoon apprentice job...

As Am f

it definitely could be - would 100% be the wrong way of doing it
possible Friday afternoon apprentice job...

Amflow appears to be strictly applying their warranty policy in Op's case. But Op said he is currently trying an in-country warranty claim in China, which might achieve something.
.
The rest of us are either affected or are sufficiently concerned, likely having bought from an authorised dealer, or second hand, or concerned what might be after the warranty expires, or regarding secondhand values.

This is how the industry tests carbon fibre bike frames for defects:

Its likely that one or more affected owners will need to bring an affected frame for lab testing if Amflow continue to 'blankly stare' at this unfolding issue.

 

[Mikerb]

I'm not sure. But the crack starts where there shouldn't be a stress point—mine is located below the crack. But if the crack has appeared and is bulging under load, and the dropper post is relatively rigid, then there's clearly a problem with the seat tube itself.

There are 2 areas on a bike frame that have to withstand the most stress. The top tube has to wjthstand compressive forces....hence using UD carbon layup. However with both carbon and ally construction those forces are then transferred to the top tube joint with the seat tube. Most especially with a carbon frame and with a narrow diameter top tube it is best to spread the load there. Could this be the problem rather than anything to do with the dropper post? The heavier the rider and /or the aggressive the rider may be more likely to get the problem.
Below is an example of how that stress point load sbould be distributed in my opinion.

 

[haromania]

Has Amflow responded and said "no" to the OP? (please don't make me read every response) Lots of people replying here, that suggest Amflow said pound sand. But did they?

...and how about the others we know of?

 

[kla456]

Has Amflow responded and said "no" to the OP? (please don't make me read every response) Lots of people replying here, that suggest Amflow said pound sand. But did they?

...and how about the others we know of?

Op has a particular situation regarding how he bought his bike (on Alibaba). He is still exploring last avenues that might get him a warranty repair. But its not about him now, because the same issue has been found in other PLs and PXs. So, its now about the rest of us Amflow owners, trying to understand what caused the issue and how widespread it might be. Amflow have not commented (to my knowledge) other than to repeat their standard warranty wording.

 

[Astro66]

because the same issue has been found in other PLs and PXs.

Whilst there are definitely isolated reports of PL seat tube cracks, that Amflow have warrantied. There appears to be no reports of PX cracks. Do you have a link to the ones you are reporting ?

 

[Plyphon]

In the UK at least, if something is shown to be not fit for purpose and/or last a reasonable length of time then the Consumer Rights Act 2015 would trump any warranty wording.

However, your statutory rights are with the retailer, not the manufacturer. This is why things get messy when you buy internationally and import. How are you going to enforce the Consumer Rights Act in another country? You're not, is the answer.

Anyway, I suspect that's why the UK Warranty for Amflow is 5 years on the frame - it would be hard to argue that if a frame breaks within 5 years that it lasted a reasonable length of time.

 

[haromania]

Op has a particular situation regarding how he bought his bike (on Alibaba). He is still exploring last avenues that might get him a warranty repair. But its not about him now, because the same issue has been found in other PLs and PXs. So, its now about the rest of us Amflow owners, trying to understand what caused the issue and how widespread it might be. Amflow have not commented (to my knowledge) other than to repeat their standard warranty wording.

Soooo, has Amflow said no? I can't tell.

 

[MeatBike]

Soooo, has Amflow said no? I can't tell.

I think Amflow told OP to contact the dealer, but the dealer is ghosting them.

 

[insplean]

Whilst there are definitely isolated reports of PL seat tube cracks, that Amflow have warrantied. There appears to be no reports of PX cracks. Do you have a link to the ones you are reporting ?

View attachment 187733

So far I have not encountered any problems with PX, only PL.

 

[kla456]

So far I have not encountered any problems with PX, only PL.

Correction to my previous post - PLs and PL Pros - not PLs and PXs