Author Topic: Checking quality  (Read 193 times)

geek81

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Checking quality
« on: January 19, 2018, 01:14:55 AM »
Hi,

I purchased my first ever carbon frame off eBay. Wondering how to check quality. The area inside the seat tube doesn't seem completely smooth (not bulging out, maybe a little pitted) the same with the headtube. The cupped part seems ok, its the area right beyond. Doesn't seem to be a structural issue - am I being to anal?



geek81

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Re: Checking quality
« Reply #1 on: January 19, 2018, 01:18:10 AM »
another image...

Klaster_1

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Re: Checking quality
« Reply #2 on: January 19, 2018, 03:00:48 AM »
Did you contact the seller yet? On the first photo a whole chunk of bearing seat looks missing, that's far from minor visual defects, but I'm not sure if it really matters in this particular place.

RS VR6

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Re: Checking quality
« Reply #3 on: January 19, 2018, 03:44:12 AM »
That does not look good. I'd contact the seller and get a replacement frame.

Bhaalgorn

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Re: Checking quality
« Reply #4 on: January 19, 2018, 07:15:09 AM »
Yeah, that's not good.... I'd be working with the seller and demanding a replacement. That's a PayPal dispute if the seller does not remedy the situation.

MTB2223

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Re: Checking quality
« Reply #5 on: January 19, 2018, 07:29:29 AM »
I don't see any problem.
The inside of the head tube doesn't have to be smooth. The bearing cups should be smooth. If the headset bearing is to tighten, you can sand down a little bit of the horizontal part, not the slanted side.
When the seat tube isn't smooth, that's also not a problem. Especially when the seat post can slide in. The part that should be smooth is the inside of the seat tube where the clamp is placed. Only this part will hold you seat post on place en should made good contact (in combination of carbon paste).

So, I shouldn't worry to much. Build up your bike and have fun....

bxcc

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Re: Checking quality
« Reply #6 on: January 19, 2018, 08:33:09 AM »
I don't see any problem.
The inside of the head tube doesn't have to be smooth. The bearing cups should be smooth. If the headset bearing is to tighten, you can sand down a little bit of the horizontal part, not the slanted side.
When the seat tube isn't smooth, that's also not a problem. Especially when the seat post can slide in. The part that should be smooth is the inside of the seat tube where the clamp is placed. Only this part will hold you seat post on place en should made good contact (in combination of carbon paste).

So, I shouldn't worry to much. Build up your bike and have fun....

I agree with most of this. I don't see much of an issue but the chunk missing from the bearing surface in the first picture may or may not cause an issue. As long as the structure around it is solid, it should be fine. Not very pretty or confidence inspiring but still functional. Same for the seat post tube. Other than the first couple of inches, it doesn't need to be overly smooth. The forward face of it should be pretty straight without much for voids. The forward face of the seatpost needs something to rest on or the seatpost will rock back and forth when sitting on the seat and pedaling which, in theory, could lead to cracking at the seat tube/top tube/seat stay junction area.

MTB2223

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Re: Checking quality
« Reply #7 on: January 19, 2018, 08:37:22 AM »
The forward face of the seatpost needs something to rest on or the seatpost will rock back and forth when sitting on the seat and pedaling which, in theory, could lead to cracking at the seat tube/top tube/seat stay junction area.
I agree. A layer of clear coat of paint will solve this issue (is my own experience). So, also not a big deal.

Don't forget, this is not an expensive brand, but a 'cheap' Chinese frame. You have to deal with this kind of small things.

Emo_gp

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Re: Checking quality
« Reply #8 on: January 19, 2018, 09:07:55 AM »
Chinese frameworks what tests go through?

geek81

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Re: Checking quality
« Reply #9 on: January 19, 2018, 09:11:38 AM »
Thanks for all feedback. I'll contact the seller and see what they say about the void in the headtube.

Its one of the BXT-015 frames, if anyone is curious. I haven't had a chance to fully unwrap it yet - wanted to keep most of it protected while I waited for parts to come in. Just unwrapped those two spots because I was curious on quality. Hoping to get started this weekend (if everything looks ok).

Thanks again.

« Last Edit: January 19, 2018, 09:15:06 AM by geek81 »