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Is my new carbon frame defective?

by drkgtkim
Sun, Feb 04, 2018 16:03
17

 

 

 

Hello. I have recently bought Eddy Merckx em525 frame and I found this bit in the head tube.

 

https://drive.google.com/open?id=179cfjeNka3T0XbBKEM_wZ-7IE3uq-1Ep

https://drive.google.com/open?id=1p2Ou-ltxPfZFZbBo1mfoKm5lqBf5g5iS

https://drive.google.com/open?id=1spbAjUt5OYINb9lJyfp1hrWw9RJ2YK_G

 

The part the yellow arrow is pointed seems to be pretty narrow to hold the weight and impact during riding.

Is it dangerous to ride on? or will it hold up?

 

 

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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17 comments

Avatar
drkgtkim | 6 years ago
0 likes

Thank you so much for sharing your knowledge lads.

I found out that the inner rim(or seat) doesn't even touch the inner side of the bearing.  I am certain that it wouldn't be a matter.

Cheers,

Avatar
LastBoyScout | 7 years ago
2 likes

Put it this way, you'd never have known if you'd bought the frame already built up.

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StraelGuy | 7 years ago
0 likes

I don't think it's anything to worry about. Looks like maybe they spotted a loose fibre or something sticking out of the resin and ground it off for aesthetic reasons. Not a real load bearing area anyway, the angular bearing just holds the steerer and stops it waggling side to side (and helps you steer obviously).

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HLaB | 7 years ago
0 likes

The links are blocked at work. Has it melted? wink

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mtbtomo | 7 years ago
1 like

Yep, doesn't look like it's needed to support the bearing. The outer race is the only bit that needs supporting on the angled surface, the inner race will mate on the fork steerer/crown (is it top or bottom bearing?) otherwise it won't spin freely.

They won't always nicely finish the bits you can't see once assembled. And if it doesn't affect the function, why would they. I've seen much worse looking down a headset tube of an old carbon Trek. It was fine.

Avatar
drkgtkim replied to mtbtomo | 7 years ago
0 likes

mtbtomo wrote:

Yep, doesn't look like it's needed to support the bearing. The outer race is the only bit that needs supporting on the angled surface, the inner race will mate on the fork steerer/crown (is it top or bottom bearing?) otherwise it won't spin freely. They won't always nicely finish the bits you can't see once assembled. And if it doesn't affect the function, why would they. I've seen much worse looking down a headset tube of an old carbon Trek. It was fine.

 

That's reassuring. It's bottom bearing. That's is why I am rather concerned about safety. It seemed to me that the seat on the bearing wouldn't fully support the weight and impact and eventually destroy the headtube, even worse, crashing.

Avatar
DaSy | 7 years ago
2 likes

The bearing is being supported by the taper, not the seat, so it shouldn't really have any impact on the weight bearing ability. You could do away with the seat altogether and still have a good interface, the seat does stop the bearing rocking and keeps it square on install, but once it's all done-up I don't see any issues.

Avatar
Canyon48 replied to DaSy | 7 years ago
0 likes

DaSy wrote:

The bearing is being supported by the taper, not the seat, so it shouldn't really have any impact on the weight bearing ability. You could do away with the seat altogether and still have a good interface, the seat does stop the bearing rocking and keeps it square on install, but once it's all done-up I don't see any issues.

Heh. Never knew that bearings were supported by taper, not the shoulder/seat. I've learnt something today and it's not even 9am 1

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drkgtkim replied to DaSy | 7 years ago
0 likes

DaSy wrote:

The bearing is being supported by the taper, not the seat, so it shouldn't really have any impact on the weight bearing ability. You could do away with the seat altogether and still have a good interface, the seat does stop the bearing rocking and keeps it square on install, but once it's all done-up I don't see any issues.

 

Thank you for your insight. So the seat is only for stabilizing  the bearing? And the inner headtube wall is where the race is supported?

Avatar
DaSy replied to drkgtkim | 7 years ago
1 like

drkgtkim wrote:

Thank you for your insight. So the seat is only for stabilizing  the bearing? And the inner headtube wall is where the race is supported?

 

The seat isn't even really a seat, it just the bit at the bottom of where they machined out the taper. The tapered wall is machined to be precisley the same angle and diameter as the bearing going into it, a bit like a glass stopper in a wine decanter. It is an angular contact bearing, because it is dealing with an axial load rather than a radial load imposed on, say, your wheel bearings.

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philhubbard | 7 years ago
0 likes

Not one of the ones from Merlin is it? Seems like have got a load extremely cheap

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drkgtkim replied to philhubbard | 7 years ago
0 likes

philhubbard wrote:

Not one of the ones from Merlin is it? Seems like have got a load extremely cheap

 

Yes, I bought this from Merlin. It was a bargain hard to pass. The frame is great except for the headset and a few missing contents(manual, seat post rubber thingy).

Avatar
djbwilts replied to drkgtkim | 6 years ago
0 likes

drkgtkim wrote:

philhubbard wrote:

Not one of the ones from Merlin is it? Seems like have got a load extremely cheap

 

Yes, I bought this from Merlin. It was a bargain hard to pass. The frame is great except for the headset and a few missing contents(manual, seat post rubber thingy).

 

...that's interesting. I've had a few items in the past from Merlin which have been a bit 'dodgy'. A pair of shoes that looked like they'd been sent out and returned a LOT(!), tires in really roughly taped up boxes that were sold as tubeless but transpired to be some weird version which weren't on Schwalbe's site, clothing that looked like returns (opened bags, missing tags).

 

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Acm | 7 years ago
0 likes

It probably would be ok, but it looks like a pretty signify defect that I doubt should've made it past QC. I'd send it back before there's a problem though

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BehindTheBikesheds | 7 years ago
0 likes

Looks like a shoddy job, I'd reject it post haste and get a full refund and try another brand.

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Canyon48 | 7 years ago
0 likes

It's probably best asking your LBS.

The outer bearing race seems to be fully supported, regardless of that small part, so I doubt it would fail.

A message to the manufacturer might be sensible.

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drkgtkim replied to Canyon48 | 7 years ago
0 likes

wellsprop wrote:

It's probably best asking your LBS.

The outer bearing race seems to be fully supported, regardless of that small part, so I doubt it would fail.

A message to the manufacturer might be sensible.

Thank you for the reply.

Yes. The outer race is fully suppored. In other words, only the half of the bearing race is supported well, which worries me.

I am waiting for the manufacturer to response.

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