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  1. #1
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    Opinions on a broken fork crown lug?

    I have a 3-year-old hefty steel touring bike from a small manufacturer that subcontracts its welding to Taiwan. I believe they buy their forks pre-assembled from a respected manufacturer. (I'm avoiding names because I don't want this to show up on a google search.)

    Last week, I was JRA and I noticed this:
    CrackedCrown.jpg

    I haven't crashed or abused the fork, other than my weighing 250#, riding it some 5000 miles on rough-paved roads, some loaded touring (though with the weight mostly on the rear), and a dynamo hub that vibrates a bit. The blades and steer tube both look perfect -- some paint chips, but no bending or buckling. No significant rust (I live in Los Angeles).

    I'm hoping to get the manufacturer to warranty the fork, but I don't have any evidence that I haven't abused it, nor do I have any evidence of a manufacturer defect other than my opinion that forks just shouldn't fail this way. I've seen lots of wrecked forks, and it's always the steer tube or blades or dropouts that are bent or broken; never the fork crown lug.

    (1) What do you think caused this?

    (2) Assuming they don't believe that I didn't abuse the fork, is there some sort of abuse I could have committed that would crack the lug but leave the fork blades and steer tube in perfect condition?

    The bike manufacturer says that the fork manufacturer will have to make the call on whether the fork is defective. I haven't talked to them yet, but when I do, I'd like to have an idea of what went on with the fork. The bike mechanics I've talked to think it's clearly a defect, but none of them do any frame work, so I was hoping to get the input of someone who has actually built a frame before.

    Thanks for your input.

  2. #2
    coprolite fietsbob's Avatar
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    New Fork ... its toast.. may have been a defective crown casting , but Its a blind Guess ..
    if its a New Bike ask at the dealership you bought the bike throuh.

    many Brands warrantee their frames for material defects, some put a Time limit on them. some ,like Trek , dont. original owner's lifetime ..

    2nd hand bike .. there would be none. you have to pay for that replacement fork .

  3. #3
    Andrew R Stewart Andrew R Stewart's Avatar
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    Hard to say the real cause but I'll take a stab and say it looks like poor brazing. The steerer bottom/crown looks to have no filler around some of it.

    As far as the warranty goes I am surprised that the bike brand is saying that they will make the fork sub contractor deal with any claim. This type of failure is the worse case type. If a complete failure you loose all control and do a face plant. The bike brand really needs to step up and take care of the OP. It's the right thing to do a a manufacturer/brand.

    I wonder if the CPSC would want to know about this? Andy.

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    I vote with Mr. Stewart on no filler. At the bottom part of the photo, I see what looks like rust. Water has been getting in there. I would say that is evidence of no filler in that area. Compare that with the fresh metal showing where the crown cracked.

  5. #5
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    Can't tell exactly from the pic, but are there two breaks emanating from the steerer tube boss? The one on the left leg looks rusty- indicating it may have been cracked for a bit, while the break on the right looks clean, and more recent. I'm guessing that the fit (steerer to crown) was too tight, which stressed the area around the hole, which would also explain the lack of filler penetration.

  6. #6
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    Oh, sorry, I should have described as well. There are the two large cracks that you can see on the left and right sides of the steer tube. The left one is rusty on the bottom, but the vertical part (cut out of this picture) is a fresh break. The right one looks fresh, except for a spot of rust where the crack reaches the steer tube, and a line of rust in the middle of the crack. There's another small one, hard to see, on the forward-right-bottom of the lug where it meets the steer tube. And then there's the crack at the top-rear of the lug, where it meets the steer tube, extending down into the brake-mount hole -- there's a little dirt or rust or something at the edge of that one, but it's hard to see.

    Thanks for your opinions here. Technically the (3-year-old) fork has a 1-year warranty, but I'm hoping the fork manufacturer will recognize a defect and decide to stand behind their product.

  7. #7
    Andrew R Stewart Andrew R Stewart's Avatar
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    At one time forks were considered a part of the frame and would be covered by the frame (and fork) portion of the warranty. Since the advent of suspension forks, and that they are produced by others then the bike brand, this changed. Now some warranties consider the fork as a component.

    Still this fork failure isn't to be downplayed. Andy.

  8. #8
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    Quote Originally Posted by jbayes View Post
    I have a 3-year-old hefty steel touring bike from a small manufacturer that subcontracts its welding to Taiwan. I believe they buy their forks pre-assembled from a respected manufacturer. (I'm avoiding names because I don't want this to show up on a google search.)

    Last week, I was JRA and I noticed this:

    I haven't crashed or abused the fork, other than my weighing 250#, riding it some 5000 miles on rough-paved roads, some loaded touring (though with the weight mostly on the rear), and a dynamo hub that vibrates a bit. The blades and steer tube both look perfect -- some paint chips, but no bending or buckling. No significant rust (I live in Los Angeles).

    I'm hoping to get the manufacturer to warranty the fork, but I don't have any evidence that I haven't abused it, nor do I have any evidence of a manufacturer defect other than my opinion that forks just shouldn't fail this way. I've seen lots of wrecked forks, and it's always the steer tube or blades or dropouts that are bent or broken; never the fork crown lug.

    (1) What do you think caused this?

    (2) Assuming they don't believe that I didn't abuse the fork, is there some sort of abuse I could have committed that would crack the lug but leave the fork blades and steer tube in perfect condition?

    The bike manufacturer says that the fork manufacturer will have to make the call on whether the fork is defective. I haven't talked to them yet, but when I do, I'd like to have an idea of what went on with the fork. The bike mechanics I've talked to think it's clearly a defect, but none of them do any frame work, so I was hoping to get the input of someone who has actually built a frame before.

    Thanks for your input.
    Jbayes; Probably comes down to how much your time is worth. Looking at the limited pix you posted, I would estimate that you could get a replacement new Chromolly fork for $30 or maybe a bit less (there are a lot of good forks on ebay, amazon, Nashbar, etc). Trim the steerer to length to fit your frame and get back on the road. On the side, from the pix showing, I sure would not want to use a replacement fork just like the one that broke. Looks like crap casting and crap brazing which rules out confidence in a factory replacement.

    If you need help selecting, read up on how to measure forks and post the data along with several pix of the broken one and we can help you find a good fit.

    /K

  9. #9
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    Resolution: Immediately upon my returning the broken fork, the bike manufacturer mailed me a replacement fork without further comment.

    Thinking that it was going to be a long slog to get the fork warrantied, I had already installed a used LHT fork so I could keep riding. I'm happy enough with the LHT fork, so I'll probably sell the new one.

    Thanks for your opinions on the cause of the failure. It appears the fork manufacturer agreed with you.

  10. #10
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    Quote Originally Posted by ksisler View Post
    Looks like crap casting and crap brazing which rules out confidence in a factory replacement.
    Point taken, but this is the first fork I've seen that failed this way. Everybody's allowed to make a mistake every once in a while, right? The brazing on the new one looks much better: there's a significant, even amount of brazing material all around the steer tube-lug interface.

    BTW, you probably already figured this out, but this fork failed slowly. It let me know it was broken and held together long enough for me to ride back home (at 5mph), resulting in zero bruises. Now I'm even less likely to buy a carbon fork than I was before.

  11. #11
    Andrew R Stewart Andrew R Stewart's Avatar
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    I've seen most every bike brand that i've sold have frame manufacturing boo boos. Bad welds/brazings, miss machined faces, missing braze ons/cable stops, cracks out of the box, miss aligned frames and forks, and more. Yet these issues are few and far between and the good companies take care of them when presented with the facts.

    It seems that this is what happened. I would look at the replacement fork closely and have no qualms about using it. But i would keep the used fork for a while. Andy.

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