Crack formed where carbon seat stay bonds to aluminum, superficial or worrysome?
07-26-12, 01:41 AM
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Crack formed where carbon seat stay bonds to aluminum, superficial or worrysome?
Jamis Nova Pro frame, noticed a crack above the carbon seat stay, presumably where the aluminum is bonded to the carbon. Is this a superficial crack due to natural flex, or is it a deeper structural issue? Taking in to my LBS for closer inspection, but wanted your opinion. Pictures are on imgur here: https://imgur.com/a/1HWmj
thanks!
thanks!
07-26-12, 02:10 AM
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Does the crack extend all the way around? does is move if pressure is applied? hard to tell what it is from the photo.
As long as you are the original owner, then it's not an issue, as Jamis have a lifetime warranty on the frame, would suspect they would replace, as with out x-raying the crack, it's hard to tell how far it goes through.
If it was mine, would be concerned, and stop using it.
As long as you are the original owner, then it's not an issue, as Jamis have a lifetime warranty on the frame, would suspect they would replace, as with out x-raying the crack, it's hard to tell how far it goes through.
If it was mine, would be concerned, and stop using it.
07-26-12, 02:38 AM
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It's almost certainly the spot where the carbon stays join the monostay; my feeling is it's not about to get any worse in a hurry, particularly if it doesn't make any noise.
That joint is in compression; I used to have a CFR1 with ally lugs and carbon tubes, and after having it a few years I noticed the bond between the seat tube and seat cluster had separated, and the tube had actually moved out of the joint by something like 3/4 of a mm. This joint sees tension, particularly when landing off a gutter or whatever, and you might expect the frame would rapidly self-destruct as a result, but it stayed the same for another year or two before it was pinched.
So I'd say it prolly looks a lot worse than it is, even though I doubt the crack is superficial and suspect the whole bond has let go. Likely a simple repair, but obviously if you're the first owner all this is academic.
That joint is in compression; I used to have a CFR1 with ally lugs and carbon tubes, and after having it a few years I noticed the bond between the seat tube and seat cluster had separated, and the tube had actually moved out of the joint by something like 3/4 of a mm. This joint sees tension, particularly when landing off a gutter or whatever, and you might expect the frame would rapidly self-destruct as a result, but it stayed the same for another year or two before it was pinched.
So I'd say it prolly looks a lot worse than it is, even though I doubt the crack is superficial and suspect the whole bond has let go. Likely a simple repair, but obviously if you're the first owner all this is academic.
07-26-12, 05:27 PM
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I agree with those who won't ride that frame. This is why I've never trusted frames made with two different materials, especially a metal and carbon (which most of them are made of). If no problem(s) with the metal properties themselves working against each other, there are sometimes adhesive issues.
07-26-12, 06:04 PM
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Is Kimmo right that the frame won't destruct catastrophically and it's ok to ride it for a while? Probably. Would I ride it in that condition? Not a chance.
I hope you are the original owner and can document the purchase. Warranty time for sure.
I hope you are the original owner and can document the purchase. Warranty time for sure.
07-26-12, 07:43 PM
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It looks like the joint between the carbon and aluminum was painted over. Maybe that's the paint cracking over the joint. I'd take steps to find out before tossing the frame. Of course, the dealer would probably know where the joint was.
07-26-12, 09:35 PM
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Bring it to the shop where you bought it.
Those frame probably cost Jamis $100 each to import from Taiwan or China... If you are the original owner then you are covered under the warranty and they will almost definitely send you a new frame.
Those frame probably cost Jamis $100 each to import from Taiwan or China... If you are the original owner then you are covered under the warranty and they will almost definitely send you a new frame.
07-26-12, 10:37 PM
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If its under warranty take it back have it taken care of if not you can have it fixed were do you live?
And take this advice Here not ours here LOL
And take this advice Here not ours here LOL
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07-27-12, 07:43 AM
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If it's not still under warranty, https://www.calfeedesign.com/repair/
I'd wrap my hand around the joint with someone else standing on the bike to flex it, and feel for movement first.
I'd wrap my hand around the joint with someone else standing on the bike to flex it, and feel for movement first.
12-28-17, 11:52 AM
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so was this a paint crack or a crack in the frame? . I have Jamis Dakota '07 and it looks the same at the spot where carbon meets alu... I've also noticed Jamis put stickers on that spot, probably to hide those paint cracks....
12-28-17, 12:14 PM
#13
don't try this at home.
The thread is 5 years old.
Most (or all?) carbon stays attached to an aluminum frame would have the end of the stay formed into a carbon plug glued inside the aluminum tube. It should be safe enough, it's essentially just a cosmetic crack.
You might try pulling apart the gap with one hand on the frame and one on the carbon stay, to see if the crack opens up at all. Riders have tried regluing those completely loose plugs, but it's not easy to make a permanent glue job.
the original photo:
Most (or all?) carbon stays attached to an aluminum frame would have the end of the stay formed into a carbon plug glued inside the aluminum tube. It should be safe enough, it's essentially just a cosmetic crack.
You might try pulling apart the gap with one hand on the frame and one on the carbon stay, to see if the crack opens up at all. Riders have tried regluing those completely loose plugs, but it's not easy to make a permanent glue job.
the original photo:
Last edited by rm -rf; 12-28-17 at 12:23 PM.
01-01-18, 10:13 PM
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Hi, it's OP. Weird to get a notification after 5 years.
I had purchased the frame on Ebay. Took it to a bike shop and they scored a small patch of the paint down to the frame, where it was clear that the crack was not just superficial but actually extended into the frame. I returned the frame to the seller and bought another.
I had purchased the frame on Ebay. Took it to a bike shop and they scored a small patch of the paint down to the frame, where it was clear that the crack was not just superficial but actually extended into the frame. I returned the frame to the seller and bought another.
