New Carbon Tubular Rim: soft spot on tire bed:



curby

New Member
May 9, 2006
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Hey ho,

New carbon tubular wheels, Yeah! Lots of holes for spoke nipples and one for the valve, right. Then there are two spots where it looks like there is a seam or something of that nature (two spots on each rim). They appear to be spots that are checked during the Quality Control check, there are colored pencil marks and one of the spots on each rim has a QC/OK sticker. Well one of the four spots has what I will describe as a 'fingernail depression' in the middle of it. Further probing reveals that the tire bed there is soft, if you pushed hard I believe you could make a hole (like if you probed it with a golf pencil). The other three spots are hard and smooth with no divots. The manufacturer says it was QC checked and is normal and dont worry about it. If it ever gives me trouble they will replace it. They also said I can wait several weeks, with no wheel, for a replacement... What do you think???
 

alienator

Well-Known Member
Jun 10, 2004
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curby said:
Hey ho,

New carbon tubular wheels, Yeah! Lots of holes for spoke nipples and one for the valve, right. Then there are two spots where it looks like there is a seam or something of that nature (two spots on each rim). They appear to be spots that are checked during the Quality Control check, there are colored pencil marks and one of the spots on each rim has a QC/OK sticker. Well one of the four spots has what I will describe as a 'fingernail depression' in the middle of it. Further probing reveals that the tire bed there is soft, if you pushed hard I believe you could make a hole (like if you probed it with a golf pencil). The other three spots are hard and smooth with no divots. The manufacturer says it was QC checked and is normal and dont worry about it. If it ever gives me trouble they will replace it. They also said I can wait several weeks, with no wheel, for a replacement... What do you think???

I wouldn't worry about it. It could be the patch over the hole from which they removed the bladder used in the molding process. What ever it is, it shouldn't affect your tires, and the tire won't load that "spot" too much.

What kind of wheels did you get?
 

curby

New Member
May 9, 2006
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Thanks, good to know, first time with this equip...

AmainT is the name on the wheels, I believe they are an OEM for some famous names, maybe Amer. Classic

The finish on the sidewalls, the true and round is really very nice, I'm glad I can keep this one because it is very true right out of the box and the spoke tension is consistent!

tnx again,
 

alienator

Well-Known Member
Jun 10, 2004
12,596
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curby said:
Thanks, good to know, first time with this equip...

AmainT is the name on the wheels, I believe they are an OEM for some famous names, maybe Amer. Classic

The finish on the sidewalls, the true and round is really very nice, I'm glad I can keep this one because it is very true right out of the box and the spoke tension is consistent!

tnx again,

Enjoy the wheels.
 

paulmurphy

New Member
Jul 2, 2003
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I suggest that you name the manufacturer. I bet they have people who read this forum; I should think added publicity could only aid your cause. Further, alerting other readers to this sort of problem is one of the main functions here.
 

alienator

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Jun 10, 2004
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paulmurphy said:
I suggest that you name the manufacturer. I bet they have people who read this forum; I should think added publicity could only aid your cause. Further, alerting other readers to this sort of problem is one of the main functions here.

I don't think there's really an issue. He's said the thin spot isn't very large, maybe the size of a spoke hole in the tire bed. It won't structurally compromise the wheel. It won't affect adhesion of his tire to the glued rim. Plus the manufacturer said he can send it in for a replacement if he wants. The company isn't trying to screw him, so I don't understand whey they would need the "added publicity."
 

paulmurphy

New Member
Jul 2, 2003
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alienator said:
I don't think there's really an issue. He's said the thin spot isn't very large, maybe the size of a spoke hole in the tire bed. It won't structurally compromise the wheel. It won't affect adhesion of his tire to the glued rim. Plus the manufacturer said he can send it in for a replacement if he wants. The company isn't trying to screw him, so I don't understand whey they would need the "added publicity."

Isn’t the purpose here to share info? If you were discussing this wheelset with a friend, would you refuse to name the manufacturer? And if their customer service is responsive and fair, let that show in the forum also.

As to the small size of the defect, (and it IS a defect), tiny discontinuities in material act as focal points for stress. The loads in such places become much higher than surrounding areas, and this is where failures will occur. Ever been on a descent doing about 50 MPH, and found yourself thinking about what would happen if your front wheel failed RIGHT NOW?! If I were the person who discovered this issue, I’d consider it my duty to let you people know. That’s what Boudreaux would have done.
 

alienator

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Jun 10, 2004
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Wow. The engineering facts you just threw out have rocked my world. Why, you must be right. Clearly you understand the loads that a CF tubular tire bed experiences.......or not. Since you don't know what rims he is talking about, you're not qualified to make your judgements. The company is. They've dealt with it.

Have you ever seen a tubular wheel? Have you ever seen or looked a CF tubular wheel? Bicycle magazine doesn't count.
 

curby

New Member
May 9, 2006
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sorry for the belated response...

AmainT is the name on the wheels, Taiwanese OEM manufacturer house label.

did I not make that clear