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Help: aluminum frame cracking at seatpost collar

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Help: aluminum frame cracking at seatpost collar

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Old 09-30-23, 05:42 PM
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celesteguy 
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Help: aluminum frame cracking at seatpost collar

Just picked this up and noticed the cracks. Haven't had time to clean it before pics. PO was a sweaty, sweaty dude.

Anyway, I assume this will get worse, is there a way to nip it in the bud? Funny thing is the crack doesn't go all the way through to the inside. (?)

My idea is to take a hacksaw and saw down the middle of the crack and then fill the saw void with bondo. Is that nuts? Should I just drill tiny holes on the ends of the cracks so it doesn't keep going? Ride as is? Idk






You can see the crack coming out of the circle that is drilled for the seatpost clamping. The rest of it just needs to be cleaned up :/

Frame is a Cervelo Soloist and is anodized. Not worried about what it looks like after a repair.

Thanks!
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Old 09-30-23, 06:53 PM
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After some research I see this was a common problem with these frames due to a brass insert being moved around right at the collar there. I also assume this insert is why the crack doesn't go through the frame; I am feeling the inside of the brass insert and the aluminum frame is, in fact, cracked through.

Can I remove the insert, drill holes at the ends of the cracks in the frame itself, reinsert the brass insert and be fine?

Most of what I read are people that just warrantied the frame and "upgraded" to carbon, so there's not a lot of info on actual fixes. I am not the original owner, so I can't do that, even though I think frames from this year were lifetimed.

Thanks!
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Old 10-01-23, 06:59 AM
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What have you got to loose by trying? (you already lost by buying it).

Seat post inserts can be simply pressed in or could be bonded in. Unsure which yours is. I don't see an issue with drilling a "stop hole" just beyond the visible crack's end (beyond because the crack's real end is so fine it might not be seen) through the tube and the insert, leaving the insert in place.

I would not saw the crack wider nor would I apply a cosmetic layer over it (Bondo). If anything you want to be able to keep an eye on the crack to track it's future growth.

Before doing anything to this I would want to inspect the rest of the frame for condition. Like the BB shell or the "braze ons" for more corrosion damage. The seat clamp area crack could be only the tip of the iceberg. Andy
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Old 10-01-23, 09:08 AM
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Thanks for your response.

I believe the insert is just pressed in. If I can remove it, I will probably do so and only drill the frame. That's my plan for now.

You are correct that I have nothing to lose since I parted this out for more than I paid for it (and could probably get a bit more for the post and forks as well) with the frameset left over. I do want to use the frameset, however.

Thanks for the advice about not sawing and also leaving the spot visible, I hadn't thought of that to be able to readily inspect it.

I'll update this week with some drilled out pics.
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Old 10-02-23, 08:16 PM
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Brass insert. Cervelo?
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Old 10-02-23, 08:23 PM
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Originally Posted by Kontact
Brass insert. Cervelo?
Yessir
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Old 10-02-23, 08:36 PM
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Originally Posted by celesteguy
Yessir
Go through a local dealer and see if they'll warranty it. Cervelo is unlikely to ask for a receipt if you say you no longer have it. Having worked at several Cervelo dealers, Cervelo sometimes acts like they just want the embarrassing old failures off the road and use their warranty powers liberally. They know that their QC has been questionable over the years.

Otherwise, wrap it in fiberglass cloth and epoxy.

Last edited by Kontact; 10-03-23 at 06:33 AM.
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Old 10-04-23, 08:45 PM
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There is a dealer just north of me. Maybe I'll stop in and see what they say before I break out the power tools. Thanks
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