# Cracked Aluminum frame after headset installation



## oren_hershco (Mar 11, 2006)

I am in the process of building a 20" wheeled bike for my kid. I decided to do it the interesting way, fully customized.

I ordered an aluminum frame and fork from Aliexpress. When they arrived, I took them to a very experienced bike mechanic for headset installation. He used a proper press for the bearing races (no hammers) Unfortunately, this is what happened (brand name is hidden):

















Questions:

1. Does this indicate a manufacturing fault or a design error?

2. Can this frame be ridden by a light boy?

3. If the seller refuses to send a new frame, can this be fixed somehow? (like drilling to stop the propagation of the crack)


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## Crispy01 (May 4, 2011)

I am sure the Manufacturer will warranty this, not safe to ride.


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## LyNx (Oct 26, 2004)

What did thew "mechanic" say happened, did he mention if it was very tight going in or if it just went in a cracked? Personally if I was installing a headset and it didn't seem to want to go in easy I'd get out the calipers and do some measuring before I went forcing it in. Hard to say what the manufacturer should do as how do they know what the "experienced mechanic" really did, the fact that it's a chinese wholesaler :skep:


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## cjsb (Mar 4, 2009)

You should not let your son ride the bike. You may have thought you were getting a great deal (but from a source known to counterfeit?). Now go to WalMart, or Costco and pay a little more.

On the specific cause, what does it matter? A properly sized head tube should not crack if the correct sized headset is properly installed.

I am also curious as to the insights of this very experienced mechanic? 

Anyway, just return it for a refund, what's the big issue?


Sent from my iPhone using Tapatalk


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## oren_hershco (Mar 11, 2006)

Answers:

This specific mechanic has learned his trade professionally in the UK, during the 90s. He's also qualified as a frame builder.

=> If he didn't feel anything awkward during the installation process, most of us wouldn't.

The headset is a WTB, so if there are some tolerances issues here, I guess they are in the frame.

To cjsb: the purpose of this project is to bulid a light, high-end kids bike. It's not a budget project. The final result will be lighter, and IMOH better than off-the-shelf high-end kid bikes, like Spawn Cycles or Early Rider. It will also cost more.

The reason for buying some of the components in Aliexpress is simply because of their availability. Some Taiwan- or China-made components are available only there (like this frame)


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## briderdt (Dec 14, 2012)

Keep us informed as to any warranty results, please. Good luck.


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## Walt (Jan 23, 2004)

You get what you pay for. 

Don't let anyone ride that.

-Walt


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## life behind bars (May 24, 2014)

Preemptive measuring is dying out apparently. Cut that thing up so no one can ever try to use it.


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## Mr Pig (Jun 25, 2008)

oren_hershco said:


> The purpose of this project is to bulid a light, high-end kids bike. It's not a budget project.


High-end and Aliexcuse in the same breath?

This is your child for goodness sake! Who wants a flashy bike, him or you? Put him on something solid and trustworthy, not cheap crap from China. What if they send you another frame and it brakes under him?

High-end!? What a joke. This thread is pissing me off...


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## briderdt (Dec 14, 2012)

oren_hershco said:


> The reason for buying some of the components in Aliexpress is simply because of their availability. Some Taiwan- or China-made components are available only there (like this frame)


There might just be a good reason for that...


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## chazpat (Sep 23, 2006)

Maybe your kids are more serious than most/mine, but they will outgrow that bike in the blink of an eye so unless they are really serious, I wouldn't spend a whole lot. I picked up a used kid's Trek off of CL for my son and when he outgrew it, sold it probably for what I paid for it and then bought a 24" Trek off CL. They were heavy steel but remembering what I did to my bike as a kid, it needed to be heavy steel. And kids care more about it looking flashy and cool than how great the components are. So you are probably doing this more for yourself than your child, which is fine if you enjoy it. I wouldn't buy anything off of Aliexpress nor most new stuff off of eBay. Aliexpress just doesn't seem like a trustworthy site.


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## cjsb (Mar 4, 2009)

I wanted a Spawn for my son,, guess what? I bought him a Spawn. When he turns 9 this year he will have gotten almost 4 years out of the frame despite his growth. This year he may be ready for a 24" wheel bike for trail riding and I will have no problem finding a good bike without Aliwhatever.


Sent from my iPhone using Tapatalk


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## Millennial29erGuy (Feb 5, 2017)

oren_hershco said:


> Questions:
> 
> 1. Does this indicate a manufacturing fault or a design error?
> 
> ...


No, no, and no! This is 100% the so-called mechanic's fault. He did not check the headtube tolerance and/or does not have access to a facing & reaming tool. Alloy frames always need to be prepped before installing the BB and headset. Please do not let your child ride this


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## thesmokingman (Jan 17, 2009)

^^That, he didn't check and ream it if necessary. If he was a mechanic since the 90's, he should have known better. From Park:

"Many headset cups are held in place by a “press fit”. The headset cup has a slightly larger diameter than the head tube inside diameter. Generally, differences of 0.1-0.25mm are considered adequate for a press fit. If the pressed cup is more than 0.3mm larger than the frame inside diameter, it may be very difficult to install, and frame damage may result."


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## oren_hershco (Mar 11, 2006)

cjsb said:


> guess what? I bought him a Spawn.
> 
> Sent from my iPhone using Tapatalk


I don't live in North America, therefore the shipping cost for a complete bike is quite high. It also makes the difference between an off-the-shelve bike to DIY bike relatively small.

I assumed people in a "frame building" forum will be pro-DIY projects, but for some reason just mentioning the word "Aliexpress" ignited an unexpected overall rage here.


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## oren_hershco (Mar 11, 2006)

the_joe said:


> Alloy frames always need to be prepped before installing the BB and headset.


Thanks, that's exactly the information I was looking for in this forum. I wasn't aware of that.



the_joe said:


> Please do not let your child ride this


After filtering-out the overall rage here, I understand this frame is not safe to ride.

The bike will not be assembled with this frame. I'll update about the seller's response.


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## oren_hershco (Mar 11, 2006)

chazpat said:


> . . . but they will outgrow that bike in the blink of an eye . . .


I'm aware of the how-much-should-you-pay-for-a-kid-bike debate. It's not the purpose of my original post, and also not the purpose of "frame building" forum. There are plenty of posts about the topic in the "Families and kids . . ." forum, and you're welcome to join them.



chazpat said:


> I wouldn't buy anything off of Aliexpress nor most new stuff off of eBay. Aliexpress just doesn't seem like a trustworthy site.


As I mentioned in another answer, I don't live in North America, therefore don't have all the variety of new and used products you have, at reasonable prices. I can give you several examples of Aliexpress products, bike-products, which have been serving me well for the last couple of years (such as the Mosso aluminum fork, which I installed on a kid-hauling bike, and performs great)

Obviously some products were crap. But their price was a fragement of their "western" equivalent, so there nothing here to lose.

I just hope mentioning Aliexpress again won't cause any secondary earthquakes here . . .


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## chazpat (Sep 23, 2006)

oren_hershco said:


> I'm aware of the how-much-should-you-pay-for-a-kid-bike debate. It's not the purpose of my original post, and also not the purpose of "frame building" forum. There are plenty of posts about the topic in the "Families and kids . . ." forum, and you're welcome to join them.


Oh, gee, thanks for the invite. And guess what, buying a frame off of Aliexpress and having a headset installed isn't exactly aligned with the purpose of "frame building" either.


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## oren_hershco (Mar 11, 2006)

chazpat said:


> And guess what, buying a frame off of Aliexpress and having a headset installed isn't exactly aligned with the purpose of "frame building" either.


Well, since I had a question about a FRAME, I assumed this forum is the most likely place to find answers. It probably is, I just wasn't aware that mentioning the evil "A" empire will spark such an emotional response.

Oh well, live and learn.


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## oren_hershco (Mar 11, 2006)

the_joe said:


> This is 100% the so-called mechanic's fault. He did not check the headtube tolerance and/or does not have access to a facing & reaming tool.


I just checked with the mechanic. He did perform the measuring, which indicated no reaming is necessary. He does have the tools.

The headset races entered the frame easily, no excessive force was needed.


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## Mr Pig (Jun 25, 2008)

oren_hershco said:


> I just hope mentioning Aliexpress again won't cause any secondary earthquakes here . . .


If you don't want to hear other people's opinions, don't ask questions on an internet forum. You're clearly not very happy about being criticized for buying cheap stuff off Aliexpress, too bad.

You freely admit that some of the stuff you've bought has been rubbish and that's the problem. You have absolutely no way of knowing which products are good and which ones aren't. If you buy parts from known brands through legitimate retailers you can be pretty confident that they are properly designed, built and tested.

Aliexpress? You've got no way of knowing any of that, and the odds are not in your favour. This is a site that's infamous for counterfeit and shoddy goods. Ordinarily I wouldn't be too bothered about what someone else is choosing to buy. If your Wang-Chung carbon bars snap and rearrange your face, well, it's your life. But this is different as you're going to Aliexpress to source safety-critical parts for your child's bike and that's not funny.

And I'm sick to death of the excuses you guys trot out for using Aliexpress. It's pathetic. It's the same with the guys who buy fake Gibson guitars from there. You do have choices. Just like they could buy an Epiphone, you could buy from Chain Reaction, buy a used bike or any number of other options but you don't and for the same reason. Ego. You want the bling but can't or won't pay the money to get the good stuff.

I hope you explain to your son that he's going to be doing some product testing for some unknown Chinese manufacturers?


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## Millennial29erGuy (Feb 5, 2017)

oren_hershco said:


> I just checked with the mechanic. He did perform the measuring, which indicated no reaming is necessary. He does have the tools.
> 
> The headset races entered the frame easily, no excessive force was needed.


Hopefully the frame manufacturer will replace it for you. It wouldn't take much force to crack a headtube like this with a headset press because the tool applies a lot of force with very little input. That said, I don't think the mechanic is being totally honest with you. But good luck!


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## Mr Pig (Jun 25, 2008)

the_joe said:


> Hopefully the frame manufacturer will replace it for you.


I expect they will replace it. My experience is that the Chinese are brilliant at refunding you or replacing broken stuff.


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## thesmokingman (Jan 17, 2009)

oren_hershco said:


> I just checked with the mechanic. He did perform the measuring, which indicated no reaming is necessary. He does have the tools.
> 
> The headset races entered the frame easily, no excessive force was needed.


Of course he did nothing wrong, which is why it is not cracked... doh! Usually as you're pressing it together, you can see bad things happen. But this mechanic clearly wasn't watching as the cups were pressed in. Bottom line, frame was not damaged until you brought it to that shop.


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## Millennial29erGuy (Feb 5, 2017)

Mr Pig said:


> I expect they will replace it. My experience is that the Chinese are brilliant at refunding you or replacing broken stuff.


Savage


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## Feldybikes (Feb 17, 2004)

I was guessing from the pictures that the headtube hadn't been reamed because it looks like it hasn't been faced, either, from the paint that's present beyond the edge of the headset. Pressing in a headset to a frame that hasn't been reamed and faced is cutting corners IMO, since it's not going to sit flat on an uneven layer of paint/powdercoat. 

That said, I've never heard of a frame cracking when pressing in a headset. And I'm wondering how this even happens when using the proper tools. I suppose it's possible the frame was never heat treated? There's only mm's of head tube beyond the weld so it's gotta be all HAZ. But still, looking at the taper from the center toot he end of the HT, it looks to be fairly beefy, so I'm kinda bewildered.

And to the OP who's confused at the reaction from this forum (and no judgement intended here, just an attempt at explanation): this forum is frequented by DIYers and some industry folks. Though assembling a bike yourself sort of seems like it's with the DIY philosophy, ordering from Aliexpress is, in another way, the antithesis of this ethos. Also, when you save some buxx by cutting out the middleman and order direct* from China, one potentially area of savings is that you might be inadvertently cutting out a QC step. Hence the "what do you expect?" attitude.

*Interestingly, I've heard that most/all of the people who are on Alibaba are actually middlemen themselves and that the only way to really go directly to the factory is to physically go directly to the factory.


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## Mr Pig (Jun 25, 2008)

thesmokingman said:


> Usually as you're pressing it together, you can see bad things happen. But this mechanic clearly wasn't watching as the cups were pressed in. Bottom line, frame was not damaged until you brought it to that shop.


The problem here is that you cannot categorically know who's fault it is. I've pressed bearings in and the press has slipped, causing the bearing to twist and jam. Careless, yes, but the frame did not break. Joe said that it doesn't take much force to break a frame like this. Actually, it does. That is assuming it's a good quality frame!

But can we assume that? Eh...nope. Decent frame manufacturers will use high-quality alloys and carry out careful heat treatments on the frame to make it as strong as possible. None of this is visible on the finished frame so it would be easy for a company to cut corners on if they wanted to knock out 'bargain' frames. This is exactly the sort of thing that the Chinese are notorious for.

If this frame was from Specialized, Giant or any other quality manufacturer you could be fairly confident that the frame is good and the break was a result of clumsy bearing fitting. It might still be but as the frame is an Aliexpress job you cannot say that for sure. I would say that it's more likely the result of a soft frame.


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## andytiedye (Jul 26, 2014)

A company named after Ali baba and the 40 Thieves.
Honest as the day is long, I'm sure.

Sent from my SM-P900 using Tapatalk


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## thesmokingman (Jan 17, 2009)

Mr Pig said:


> The problem here is that you cannot categorically know who's fault it is.


We don't know the details or facts categorically, but I do know that this should not have happened, end of story. In the worst case someone should have seen the crack develop and stopped, pull out the CYA card but that did not happen. Some great mechanic... huh? Doesn't notice he's cracking the headtube till its way too late and he's assembled everything before noticing? WTH?


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## Mr Pig (Jun 25, 2008)

andytiedye said:


> A company named after Ali baba and the 40 Thieves.
> Honest as the day is long, I'm sure.


I just had a quick look at the frames on the site, until my anti-virus software popped up a warning! They sell 'genuine' big-brand frames!

Have a read: LINK


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## Mr Pig (Jun 25, 2008)

thesmokingman said:


> Some great mechanic... huh? Doesn't notice he's cracking the headtube till its way too late and he's assembled everything before noticing? WTH?


Maybe you're looking it that wrong?

If I was fitting a headset and it was really tight, went in squint or there was a cracking noise, I'd stop and have a look at at when was going on. The fact that this guy carried on assembling suggests to me that he thought it was going fine and nothing unusual was happening. You're only seeing one possible conclusion here and I don't think that's fair.


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## m-gineering (Feb 5, 2012)

drawn tubes are pretty anisotropic. ie pretty strong lenghtwise, but fairly weak across the grain. So all frames I've seen where excessive stress cracked the headtube have the crack vertically. SO why is the crack here at 45 degrees?


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## cjsb (Mar 4, 2009)

OP you are way too sensitive and seem to expect that replies only address the technical aspects of your questions. There are a lot of knowledgeable folk on this site and especially in frame forum, but one cannot divorce the technical question from the quality of the frame and its source. You get free and unfiltered advice on public forums.

To give you more unsolicited feedback, the circumstances you described make the explanation sound sketchy. Still, the simplest explanation is usually the right one and in this case it is: buying a frame from a source known to deal in counterfeits is quite risky, especially for higher "quality" items. You thought you got one over but Ali and his thieves got one over on you that's all. If they have solid return policy then no biggie, treat it like damaged in transit and roll the dice with them again since you have constraints that seem to dictate this as your best option. 

Nothing in this post was written with rage or anger.


Sent from my iPhone using Tapatalk


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## oren_hershco (Mar 11, 2006)

Update: the manufacturer claims it's the mechanic's fault. Since it's almost impossible to know the actual cause, this becomes a dead end.

The Aliexpress seller has REMOVED this frame from the site, less than 24h ago. This product is no longer available.

Right know I'm looking for a known brand bike, which I can strip for the frame (since I already have better components)

Thank you all for the deep knowladge reflected in your replies.

I'll update about the final result in the "Families and ..." forum.


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## Walt (Jan 23, 2004)

Don't worry, it'll be back with a new name being sold by the original seller's cousin or something soon.

-W


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## VegasSingleSpeed (May 5, 2005)

m-gineering said:


> drawn tubes are pretty anisotropic. ie pretty strong lenghtwise, but fairly weak across the grain. So all frames I've seen where excessive stress cracked the headtube have the crack vertically. SO why is the crack here at 45 degrees?


Because of the weld.

I'm a bit interested in the weld extending to the top of steerer tube, no parent metal is above the weld to maintain continuity in the original circumferential structure of the tube; how much parent metal is still left in that area of the headset cup (e.g. there could be a half-inch of burn-through on that side of the headset cup that was machined to appear nice)? Throw in the possibility of a shoddy stress-relief/heat-treatment (or none whatsoever).

I'm not quick to blame the mechanic. The headset could have pressed in just fine without cracking, but the first square bump the rider hit (leveraging the top of the steerer forward) *could have* produced that same crack (assuming the headtube was compromised to begin with due to manufacturing...).


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## gumby. (Mar 11, 2013)

Feldybikes said:


> I suppose it's possible the frame was never heat treated?


Then it would be softer with greater yield



m-gineering said:


> drawn tubes are pretty anisotropic. ie pretty strong lenghtwise, but fairly weak across the grain. So all frames I've seen where excessive stress cracked the headtube have the crack vertically. SO why is the crack here at 45 degrees?


Because engineering 101 'Stress Raiser'



cjsb said:


> Still, the simplest explanation is usually the right one and in this case it is


Too tight


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## thesmokingman (Jan 17, 2009)

Mr Pig said:


> Maybe you're looking it that wrong?
> 
> If I was fitting a headset and it was really tight, went in squint or there was a cracking noise, I'd stop and have a look at at when was going on. The fact that this guy carried on assembling suggests to me that he thought it was going fine and nothing unusual was happening. You're only seeing one possible conclusion here and I don't think that's fair.


No, I'm not looking at it wrong. I'd be serious pissed at any mechanic. And it goes to show the level of awareness with said mechanic. The fact that he goes thru the process of putting the fork on and all the accoutrements lmao, and the head tube is cracked, like WTF!? And it wasn't fine, obviously so thinking it is fine without noticing and being sure is just negligent.


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## VegasSingleSpeed (May 5, 2005)

***


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## Mr Pig (Jun 25, 2008)

thesmokingman said:


> No, I'm not looking at it wrong.


Well that's like just, uh.... your opinion man.


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## leeboh (Aug 5, 2011)

oren_hershco said:


> Update: the manufacturer claims it's the mechanic's fault. Since it's almost impossible to know the actual cause, this becomes a dead end.
> 
> The Aliexpress seller has REMOVED this frame from the site, less than 24h ago. This product is no longer available.
> 
> ...


 Ask me no questions I'll tell you no lies. That cheap chinese stuff is awesome? Frame specs? Might be easier just to get good, used working bike and give a clean, lube and overhaul.


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