CAAD12 - dented top tube: thoughts?

Discuss light weight issues concerning road bikes & parts.
bremerradkurier
Posts: 272
Joined: Mon Jun 13, 2016 4:18 pm

by bremerradkurier

Maybe apply dry ice to the dent after the tube has been heated with a hair dryer and see if it pops out?

https://diy-auto-repair.wonderhowto.com/how-to/fix-car-dent-with-dry-ice-271175/

by Weenie


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573
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Joined: Wed Sep 05, 2012 2:38 pm
Location: West Sussex, UK.

by 573

So I decided to ride it. I headed off up a climb, in a big gear, out of the saddle to put lots of torque through the bike. At the top, the dent seemed to have lost its 'soft' appearance and now has more of a crease to it. There are now also 'stress' lines to each side of the dent.

Image

Image

I descended slowly and parked it up. I think that may be it for this frame, I have no confidence in it now.

Broady
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Joined: Thu Jan 03, 2013 5:02 pm

by Broady

Eeesh yeah that does look worse now, not sure I'd carry on riding that.

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kgt
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Location: Athens, Greece

by kgt

I would not ride it. IMO the top tube will snap the moment the front wheel falls in the first pothole.

topflightpro
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Joined: Tue Jan 13, 2009 2:35 am

by topflightpro

I think you're still OK to ride it, but keep an eye on those stress marks that are visible on the second photo.

If they start getting more defined, then it's time to hang it up.

antonioiglesius
Posts: 290
Joined: Sat Oct 15, 2016 9:08 pm

by antonioiglesius

I still can't believe a conker did this...

OP: did you ask the shop/Cannondale to see if they can do something about it?

srshaw
Posts: 171
Joined: Sun Apr 05, 2015 6:06 pm

by srshaw

I don't think that's safe now. I guess the forces from the head tube would push the top tube down as the front wheel hits a bump. That looks as though it will just crease further.

I doubt that would've have been covered by warranty anyway since it wasn't a defect from manufacturing but an accident that caused it.

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573
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Joined: Wed Sep 05, 2012 2:38 pm
Location: West Sussex, UK.

by 573

I now need to decide what to do next, do I:

- buy the sparkly purple 2017 CAAD12 disc framset that's available at a reduced price currently (~£650 (GBP)) and swap the parts from this bike over
- buy one of the 2017 CAAD12 disc bikes that are currently available in the end-of-season sale (105 @ ~£1100 / Ultegra @ ~£1650) and swap the wheels etc over and sell the remainder of the bits of both bikes off
- stick mudguards on my Evo, fit my standard Mavic Aksiums to it and ride it through the winter and then treat myself to a new summer bike in the spring (Hi-Mod Etap probably...)

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53x12
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Joined: Fri Sep 15, 2006 6:02 am
Location: On the bike

by 53x12

53x12 wrote:Guess you got yourself a new indoor trainer bike.


Bump. Take it off the road. Use it as an indoor trainer bike. Don't risk severe injury or worse by riding it on the road further.
"Marginal gains are the only gains when all that's left to gain is in the margins."

Alexandrumarian
Posts: 202
Joined: Mon Mar 28, 2016 6:34 pm
Location: Romania

by Alexandrumarian

I can't remove this scary image from my mind: an evil squirrel tried to kill you with a slingshot...

Seriously now, how about repairing it with several wrapped layers of carbon cloth and epoxy? Would act as a lug taking off most stress from the sunk area.

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choiboi
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Joined: Sun Aug 15, 2010 2:38 pm

by choiboi

Cheaper to replace frame than teeth.

Can't believe a conker did that!

Sent from my ONEPLUS A5000 using Tapatalk
David
[b]'10 CANNONDALE CAAD10

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573
Posts: 247
Joined: Wed Sep 05, 2012 2:38 pm
Location: West Sussex, UK.

by 573

Replacement CAAD12 disc frameset bought; the sparkly purple colourway swung it for me. Will try to avoid riding this one under conker trees...

Essentially it came down to the fact that even if this frame is OK, I just don't have confidence in it. I won't enjoy riding it as I'll always have a concern in the back of my mind that it might fail.

If anyone else wants to take a risk on the frameset (inc carbon fork etc) then drop me a message; will obviously be cheap.

darnellrm
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Joined: Thu Sep 10, 2009 1:06 pm
Location: NC, USA

by darnellrm

We constantly read all the fear mongering about carbon fiber bikes being so fragile, but high-end thin wall aluminum and steel tubes are even easier to damage, even though they may not crack immediately. And worse yet, they cannot be repaired ( at least not at a reasonable price ). If this were a carbon fiber frame, it could have been good as new for $200, but I would place a large wager that it would have not been damaged in the first place.

FWIW.

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573
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Location: West Sussex, UK.

by 573

I have to agree, I doubt hugely that a conker would have damaged my Evo.

Both materials have different properties and both have their achilles heels. If you hydroform aluminium and shape it and stretch it out with the aim of reducing weight by making the tubes very thin in the middle where torsional strength isn't required then you obviously make that area more susceptible to impact damage.

Really though, my CAAD frame may be fine for many more thousands of miles. I'm just not happy riding it.

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kgt
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Location: Athens, Greece

by kgt

Superlight alu was never a great idea. I remember De Rosa Ud or Bianchi EV4 around 1000-1100gr. Nice frames but for a season or two only.

by Weenie


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